Seismic evaluation of various Yukon schools [16.75 MB ]

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DNA
project managers
planners
architects
engineers
David Nairne + Associates
Suite 250
171 W Esplanade
North Vancouver
British Columbia
Canada V7M 3J9
T 604 984 3503
F 604 984 0627
E info@
davidnairne·com
SEISMIC EVALUATION
OF VARIOUS YUKON SCHOOLS
Whitehorse
Selkirk
Nelnah Bessie John
Kluane Lake
Takhini
Christ the King
St. Elias Community
Wood Street Centre
August 28, 2013
Prepared For:
Yukon Government
Education
Box 2703, (E-1)
1000 Lewes Boulevard
Whitehorse, Yukon Y1A 2C6
Contract No: C00017663 & C00017664
Prepared By:
DNA 5143/5144
Commissioned By:
Yukon Government
Capital Development, PMD
Highways and Public Works
P.O. Box 2703, (W-5)
Whitehorse, Yukon Y1A 2C6
SEISMIC EVALUATION OF VARIOUS YUKON SCHOOLS
August 28, 2013
EXECUTIVE SUMMARY
In 2010, the Yukon Government retained David Nairne + Associates Ltd. (“DNA”) to carry
out a seismic screening of twenty-seven Yukon School Buildings for the Department of
Education. The seismic screening identified five schools located in Whitehorse and three
schools in the Yukon as medium to high seismic risk that warranted further evaluation:
Kluane Lake, Nelnah Bessie John, St. Elias Community, Wood Street Centre, Christ the
King, Selkirk, Takhini and Whitehorse Elementary.
In 2013, the Yukon Government retained DNA to carry out a subsequent seismic evaluation
of these eight schools to identify seismic deficiencies and corresponding retrofit concepts
and to prepare a Class 4 cost estimate with respect to the National Building Code of
Canada (NBC) 2010 (Commentary L & NRC Guidelines for the Seismic Evaluation of
Existing Buildings).
With respect to the NBC 2010, the level of seismicity is classified as Moderate for the five
Whitehorse schools and High for other three schools.
There are seismic deficiencies in all eight of the schools with respect to the NBC 2010.
The type and severity of the deficiencies vary from school to school. In general, the
deficiencies can be categorized as occurring in the roof, floors, walls, foundations and nonstructural. DNA developed seismic retrofit concepts to address these seismic deficiencies
and prepared corresponding cost estimates. Hazardous building materials are likely
present in all of the schools and should be removed/abated during the construction of the
seismic upgrading.
School
Location
Year
Originally
Built
Seismic Upgrading
Cost Estimate
Kluane Lake
Destruction Bay
1961
$516,889
Nelnah Bessie John
Beaver Creek
1961
$516,889
St. Elias Community
Haines Junction
1963
$1,758,009
Wood Street Centre
Whitehorse
1954
$2,431,819
Christ the King
Whitehorse
1960
$3,579,058
Selkirk
Whitehorse
1958
$2,460,576
Takhini
Whitehorse
1960
$1,538,686
Whitehorse Elementary
Whitehorse
1950
$6,671,123
1.
2.
3.
4.
ASTM Class 4 Cost Estimate
2013 Canadian dollars
Soft costs are excluded
See Section 6.0 for additional information relating to the cost estimate.
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August 28, 2013
TABLE OF CONTENTS
EXECUTIVE SUMMARY
i
1.0
1.1
1.2
1.3
TERMS OF REFERENCE
2010 Seismic Screening
2013 Seismic Evaluation
Conditions and Limitations
2
2
2
2
2.0
2.1
2.2
2.3
SEISMIC EVALUATION METHODOLOGY
Seismic Evaluation and Upgrading Process
Evaluation Standard
Seismic Evaluation Procedure
3
3
3
4
3.0
3.1
3.2
3.3
3.4
SEISMIC PARAMETERS
Spectral Response Acceleration
Site Class
Importance Factor
Level of Seismicity
5
5
5
5
6
4.0
4.1
4.2
GEOTECHNICAL CONSIDERATIONS
Soil Bearing Capacities
Liquefaction Potential
6
6
6
5.0
5.1
5.2
5.3
5.4
5.5
BUILDING STRUCTURE PARAMETERS
Year of Construction
Building Shape and Irregularities
Construction Materials and Building Weight
Structural Systems
Non-Structural Components
7
7
7
7
7
8
6.0
6.1
6.2
6.3
6.4
SEISMIC UPGRADING COST ESTIMATE
ASTM Cost Estimate Method
Cost Categories
Allowances
Costs Not Included
8
8
9
9
9
7.0
FINDINGS
10
APPENDIX A
Class 4 Cost Estimate Summary
APPENDIX B
Desktop Study Seismic Screening of Selected Yukon School
Building Sites EBA Engineering Consultants Ltd
SCHOOL REPORTS
KLUANE LAKE ELEMENTARY
NELNAH BESSIE JOHN
ST. ELIAS COMMUNITY
WOOD STREET CENTRE
CHRIST THE KING ELEMENTARY
SELKIRK ELEMENTARY
TAKHINI ELEMENTARY
WHITEHORSE ELEMENTARY
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1.0
TERMS OF REFERNECE
1.1
2010 Seismic Screening
August 28, 2013
The Yukon Government retained David Nairne & Associates Ltd. (“DNA”) in 2010 to
carry out a seismic screening of 27 Yukon School Buildings for the Department of
Education. The purpose of the seismic screening was to identify medium to high
seismic risk buildings that warrant further evaluation. DNA carried out the seismic
screening by applying the methodology and screening tools contained in the
Manual for Screening of Existing Buildings for Seismic Investigation (”The NRC
Screening Manual”) prepared by the National Research Council of Canada in 1992.
The seismic screening identified eight Yukon schools as medium to high seismic
risk that warranted further evaluation.
1.2
2013 Seismic Evaluation
In 2013, the Yukon Government retained DNA to carry out the subsequent
evaluation of these eight, medium to high seismic risk Yukon schools:
Yukon Schools
Whitehorse Schools
Kluane Lake
Nelnah Bessie John
St. Elias Community
Wood Street Centre
Christ the King Elementary
Selkirk Elementary
Takhini Elementary
The purpose of this evaluation is to determine the seismic risks associated with
each school; to identify preliminary seismic retrofit concepts addressing these
seismic risks; and to prepare a cost estimate for the seismic retrofits. The
evaluation of the schools is to be carried out using the National Building Code of
Canada 2010 (NBC 2010).
1.3
Conditions and Limitations







DNA has prepared this report for the exclusive use of the Yukon Government.
Our findings are based on visual observations made during our time on site and our
review of available drawings only, along with our professional experience and
judgment.
No materials testing or hazardous materials investigations were carried out as part
of this project.
Where construction details are unknown due to missing drawings or lack of
information on available drawings, our findings are based on assumptions using
judgment.
No detailed design or drawings were carried out as part of the development of this
report.
Our findings and opinion of probable costs are solely intended to assist the Yukon
Government in planning for seismic upgrading and are not a quotation for
construction.
This report is subject to review and revision should additional information become
available and/or should further investigations be undertaken.
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2.0
SEISMIC EVALUATION METHODOLOGY
2.1
Seismic Evaluation and Upgrading Process
August 28, 2013
The seismic evaluation and upgrading of existing buildings typically involves three
phases:
2.2
Phase
Description
Phase 1
Seismic Screening
Screen buildings to rank and prioritize them according
to seismic risk, and identify buildings that warrant
further seismic evaluation. In 2010, DNA carried out a
Phase 1 Seismic Screening of 27 Yukon schools that
identified 8 schools as medium to high seismic risk.
Phase 2
Seismic Evaluation
Further evaluate medium to high seismic risk buildings
to identify the nature and extent of the seismic
deficiencies; to develop seismic upgrading options; and
to prepare cost estimates. The scope of this report falls
under Phase 2.
Phase 3
Seismic Upgrading
Prepare detailed design drawings and specifications for
the construction of the seismic upgrading.
Evaluation Standard
National Building Code of Canada 2010
As mandated by the Yukon Government, the seismic evaluation is based on the
NBC 2010. The NBC 2010 was developed for the design and construction of new
buildings and not for the evaluation and upgrading of existing buildings. As a
result, using the NBC 2010 to evaluate the structural and seismic capacity of an
existing building can often require costly upgrading.
NBC 2010 Commentary L
To address this issue, the NBC provides an alternate approach in the evaluation of
existing buildings by referencing the use of Commentary L contained in the User’s
Guide – NBC 2010 Structural Commentaries. Commentary L provides guidance
and criteria in the evaluation and upgrading of existing buildings and recommends
following the NRC Guidelines for the Seismic Evaluation of Existing Buildings (NRC
Guidelines).
NRC Guidelines for the Seismic Evaluation of Existing Buildings
The NRC Guidelines were used for the seismic evaluation of the eight Yukon
schools. The NRC Guidelines were specifically developed to aid in the seismic
evaluation of existing buildings by modifying the criteria in the NBC 2010. These
guidelines are designed to meet the basic life-safety objectives of the NBC by
identifying the structural deficiencies that have typically led to failures in past
earthquakes and that present unacceptable life safety risks. Furthermore, the NRC
allows use of reduced load factors to decrease the loads specified in the NBC
2010. In the case of earthquake loads, the NRC Guidelines allow the use of a load
factor of 0.60, resulting in earthquake loads equal to 60% of those required by the
NBC 2010. In essence, the NRC Guidelines does not require seismic grading if the
seismic capacity of an existing building is equal to or greater that 60% of the
seismic capacity required by the NBC 2010.
Where seismic upgrading is required, the seismic upgrading is to be designed in
accordance with the regular provisions in the NBC 2010.
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2.3
August 28, 2013
Seismic Evaluation Procedure
DNA carried out a seismic evaluation of the eight Yukon schools in accordance
with the procedure outlined in the NRC Guidelines.
Step 1: Document Review
DNA obtained from the Yukon Government all relevant building documents,
including architectural drawings, structural drawings, geotechnical reports and
school building condition reports contained in a 1995 Yukon Whitehorse School
Facilities Study and a 1996 Yukon Rural School Facilities Study.
The drawings were used to help determine the dates of construction of the original
building and subsequent additions and renovations; to identify the building
configuration, type of construction and building materials used; and to ascertain the
structural systems used to resist earthquake ground motions.
For the purposes of the seismic evaluation, we subdivided each school into distinct
building “Blocks” that represented a significant change in configuration, year of
construction, structural system and/or construction materials.
Step 2: Site Visit
Jerry Lum of DNA carried out a site visit of each school between April 22, 2013 and
April 26, 2013. The site visits involved a walk-through visual examination of the
readily accessible areas of each school building to verify the general construction of
each school compared to the original drawings; to assess the general structural
condition of each school; and to evaluate the seismic deficiencies at each school.
Step 3: Structural Evaluation
The NRC Guidelines contain numerous Evaluation Statements that are formulated
to help identify structural deficiencies in existing buildings similar to those that have
contributed to building failures in past earthquakes. Following a review of drawings
and a site visit, the Evaluation Statements are answered, and potential structural
deficiencies are identified. After this point, specific building components may be
determined to be safe; certain building components may necessitate upgrading
without additional analysis; and/or some building components may require
additional investigation to determine whether or not upgrading is required. Upon
completion of the evaluation process, seismic deficiencies are identified; seismic
retrofit options are developed and cost estimates are prepared.
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3.0
August 28, 2013
SEISMIC PARAMETERS
The level of seismicity at a particular building site is based on three key parameters:
Spectral Response Acceleration, Site Class and Importance Factor.
3.1
Spectral Response Acceleration
The level of ground motion at a building site is represented numerically by the
Spectral Acceleration and Peak Ground Acceleration. The values for each of these
parameters are based on a probability of exceedance of 2% in 50 years. Higher
values generally represent a higher potential level of ground motion.
Location
Whitehorse
Beaver Creek
Haines Junction
Destruction Bay
3.2
Spectral
Acceleration
Sa(0.2)
0.22
0.73
0.72
0.73
Peak Ground
Acceleration
PGA
0.11
0.33
0.33
0.33
Site Class
Ground motions generated by an earthquake are highly influenced by the
composition of the soils underlying the building site. The soils at a particular site
can be categorized into one of six different “Site Classes” ranging in severity from
Site Class A (“Hard Rock” with low intensity surface ground motions) to Site Class
F (“Soft Soil” with high intensity surface ground motions). Significant amplification
of ground motions can occur at sites with soft soil conditions.
The Yukon Government retained EBA Engineering Ltd. (“EBA”) to complete a
desktop study (See Appendix B) in order to provide site classifications and soil
bearing capacities for each school. The site classification of each school is
summarized below.
School
Site Class
Fa
Site Class E
2.1
Wood Street Centre
Site Class E
2.1
Site Class E
2.1
Selkirk Elementary
Site Class E
2.1
Takhini Elementary
Site Class E
2.1
Kluane Lake
Site Class D
1.1
St. Elias Community
Site Class D
1.1
Nelnah-Bessie Johnson
Site Class D
1.1
Note: Fa is an acceleration-based site coefficient that is a function of the Site
Class and the Spectral Response Acceleration. Higher values represent a
higher amplification of ground motions at the ground surface.
3.3
Importance Factor
The Importance Factor, IE, is used to define a level of importance assigned to a
building based on its use and occupancy. The majority of buildings are classified
as ‘Normal’ importance and are assigned an importance factor, IE = 1.0. Schools,
however, are classified as ‘High’ importance and assigned an importance factor of
IE = 1.3. Schools with an IE of 1.3 must be designed to resist earthquake forces
that are 130% higher than normal buildings to reduce the probability of damage
and to incorporate more reserve capacity into the structure’s lateral system.
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3.4
August 28, 2013
Level of Seismicity
The level of seismicity at each school building site is determined by a combination
of the Spectral Response Acceleration (Sa(0.2)), Site Class (Fa) and Importance
Factor (IE) for each particular school:
IEFaSa(0.2)
FaSa(0.2) < 0.12
IEFaSa(0.2) < 0.35
0.35 ≤ IEFaSa(0.2) < 0.75
IEFaSa(0.2) ≥ 0.75
Level of Seismicity
Negligible
Low
Moderate
High
Based on the parameters above, the level of seismicity for each of the eight
schools is summarized below:
School
Wood Street Centre
Selkirk Elementary
Takhini Elementary
Kluane Lake
St. Elias Community
Nelnah-Bessie John
IEFaSa(0.2)
0.60
0.60
0.60
0.60
0.60
1.04
1.03
1.04
4.0
GEOTECHNICAL CONSIDERATIONS
4.1
Soil Bearing Capacities
Level of Seismicity
Moderate
Moderate
Moderate
Moderate
Moderate
High
High
High
EBA’s report provided soil bearing capacities for shallow foundations for each
school:
School
Wood Street Centre
Selkirk Elementary
Takhini Elementary
Kluane Lake
Saint Elias
Nelnah-Bessie John
4.2
Unfactored Soil Bearing Capacity (kPa)
Spread Footing
Strip Footing
500-850
300
700-850
500
1200-1450
750
600-1350
N/A
1150
500-650
300
200
700
450-800
450
300
Liquefaction Potential
EBA’s report indicated that liquefaction potential does not need to be considered in
the evaluation of the foundations for any of the eight schools in this report.
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5.0
August 28, 2013
BUILDING STRUCTURE PARAMETERS
There are several aspects of a building structure that impact its response to
seismic ground motions.
5.1
Year of Construction
The requirements in the National Building Code for earthquake design have evolved
significantly over the past fifty years with knowledge and research gained from
building performance in past seismic events. The year of construction is usually a
good representation of the level of consideration that was given to seismic detailing
in the building at the time of construction. In the past, there was less knowledge
about building performance in earthquakes than there is today. In general, older
buildings represent a higher seismic risk than newer buildings.
5.2
Building Shape and Irregularities
The overall shape and configuration of a building has an influence on its response
to earthquake ground motions. Basic form buildings perform more regularly;
whereas buildings with irregular configuration characteristics are more susceptible
to stress concentrations and other non-favourable conditions. Some of these
configuration characteristics or irregularities include:
 The strength or stiffness of one storey is substantially different than that in
a storey above or below.
 The weight of one storey is substantially different than that in other storeys.
 The plan dimensions of the building change significantly from one storey to
another.
 There are in-plane or out-of-plane offsets in the lateral force resisting
system.
 The distribution of lateral force resisting elements is such that the building
is sensitive to torsion.
5.3
Building Weight
Seismic forces are directly proportional to the weight of a building. Heavier
buildings pose a higher seismic risk than lighter buildings due to more mass that
accelerates in response to earthquake ground motions. Structural systems using
concrete and masonry result in heavier buildings than those built with steel or
wood. Heavy non-structural components, such as stucco wall finishes, concrete
floor toppings, tile roofs, etc., also contribute to higher building weights.
5.4
Structural Systems
Schools are constructed with a variety of structural systems and materials with the
most common materials being concrete, steel, wood and masonry. These
materials are utilized to resist the gravity and lateral loads that a building may be
subjected to over its life span. Each of these materials performs different in
response to earthquakes, depending on the type of structural system in the
building. Gravity and lateral systems typically include moment frames, shearwalls
and braced frames. The ability of a certain material to continue to carry the gravity
loads it supports, while undergoing lateral drift in response to earthquake ground
motions, is an important characteristic to consider when evaluating a building’s
potential seismic response. Each of the structural systems has different strength
and stiffness characteristics. For example, concrete shearwalls are typically stiffer
and stronger than masonry and wood-frame shearwalls. Shearwalls are typically
stronger and stiffer than cross braces and moment frames of the same material.
Furthermore, a building with a series of lateral force resisting elements, such as
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August 28, 2013
shearwalls or cross braces, has a higher level of redundancy than buildings with
only a single lateral force resisting element. Buildings with more redundancy are
less dependent on the successful performance of a single element, where failure
could preclude the collapse of the entire building in scenarios where there are a
limited number of lateral elements.
5.5
Non-Structural Components
Although the seismic assessment of non-structural components was not included
in the scope of this report, certain non-structural components can pose a
significant life safety risk during an earthquake. These non-structural components
include heavy exterior falling hazards, such as masonry or concrete parapets or
walls, unreinforced or unbraced masonry chimneys, masonry veneer, and
stone/pre-cast panels. Heavy interior falling hazards include masonry partition
walls, heavy equipment, lockers, and book/storage shelving. Falling hazards in
means of egress, such as corridors, stairs and exits, are of particular concern.
Our report only identifies heavy partition walls and chimneys that may be a falling
hazard during an earthquake.
6.0
SEISMIC UPGRADING COST ESTIMATE
6.1
ASTM Cost Estimate Method
The cost estimate for the seismic upgrading of each school was prepared
according to ASTM E2516-11 for a Class 4 estimate. The expected accuracy
range for a Class 4 cost estimate varies between +30% to -20% for a project that
is defined up to 15% complete.
Our cost estimates are offered as probable costs of construction to assist the
Yukon Government in planning for seismic upgrading and not as a quotation for
construction. They are based on our site visit, seismic evaluation to date, available
information and conceptual seismic retrofit options. The cost estimate allows for
any upgrading of existing non-structural building components to current building
code that may be affected by the seismic upgrading (eg new insulation, new
windows, etc).
In order to provide more detailed and accurate cost estimates, further site
investigation, evaluation and detailed design will need to be carried out, and
drawings and specifications will need to be prepared.
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6.2
August 28, 2013
Cost Categories
In the individual school reports, seismic deficiencies and retrofit concepts are listed
as being applicable to certain parts of the building’s structural system: roof, upper
floor, main floor, walls, foundation, miscellaneous/non-structural, and hazardous
materials. To maintain coordination between the cost estimate and the retrofit
concepts for each of the seismic deficiencies, seismic upgrade cost estimates are
tabulated for each of those individual categories. (For example, the cost estimate
provided for the ‘Roof’ in one of the school blocks would apply to all of the seismic
deficiencies and retrofit concepts presented in the ‘Roof’ section for that school
block.) Having said that, summarizing the costs into individual categories is only
meant to provide a general breakdown of costs. In reality, there will be significant
overlap across the categories, so cost estimates for individual categories should
not be utilized for planning purposes in isolation from the other categories. (As
another example, an allowance for removing wall finishes may be lumped into the
‘Walls’ category; however, a roof diaphragm load path upgrade may also require
removal of some wall finishes. Since the removal of wall finishes would already be
considered in the ‘Walls’ category, it would not also be added as a cost to the
‘Roof’ category.)
6.3
Allowances
The cost estimate includes allowances for several components that cannot be
clearly defined at this stage of our assessment:
Component
Miscellaneous architectural restoration
10 %
Mechanical removal/reinstallation
5%
Electrical removal/re-installation
3%
Hazardous materials assessment, removal and abatement
6.4
Allowance
$ 10 / sf
General contractor overhead, profit, insurance, mobilization, etc.
20 %
Consultant fees
15 %
Construction contingency
20 %
Costs Not included
Our cost estimate includes the design and construction of the seismic upgrading of
each school and does not include soft costs such as taxes, moving costs,
temporary facilities (e.g. portable classrooms, storage facilities, etc.), loss of
use/revenue, building permit fees, client administration time, etc.
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August 28, 2013
7.0
FINDINGS
7.1
DNA carried out the seismic evaluation of Kluane Lake Elementary, Nelnah Bessie
John, St. Elias Community, Wood Street Centre, Selkirk Elementary, Whitehorse
Elementary, Takhini Elementary and Christ the King Elementary using the NBC
2010 Commentary L and the NRC Guidelines for the Seismic Evaluation of Existing
Buildings.
7.2
We identified seismic deficiencies in each of the eight Yukon schools with respect
to the NBC 2010. These deficiencies and associated seismic upgrading concepts
are described in detail in the individual school reports attached.
7.3
DNA prepared cost estimates for the seismic upgrading of each school:
School
Location
Year
Originally
Built
Seismic Upgrading
ASTM Class 4
Cost Estimate
Kluane Lake
Destruction Bay
1961
$516,889
Nelnah Bessie John
Beaver Creek
1961
$516,889
St. Elias Community
Haines Junction
1963
$1,758,009
Wood Street Centre
Whitehorse
1954
$2,431,819
Christ the King
Whitehorse
1960
$3,579,058
Selkirk
Whitehorse
1958
$2,460,576
Takhini
Whitehorse
1960
$1,538,686
Whitehorse
1950
$6,671,123
a. See Appendix A and the individual school reports for details.
b. See Section 6 Seismic Upgrading Cost Estimate for conditions of the cost
estimate.
To develop more accurate cost estimates of the seismic upgrading, detailed site
investigation, design, drawings and specifications will need to be completed.
7.4
Hazardous building materials, (e.g. asbestos, vermiculite and lead paint) are likely
present in schools and we recommend that Yukon Government commission a
hazardous materials assessment of the schools prior to the construction of any
seismic upgrading. Our cost estimate above includes an allowance of $10 per
square foot of floor area for the abatement/removal of hazardous building materials.
7.5
As an alternate assessment approach to the 2010 NBC, DNA is able to carry out a
subsequent seismic evaluation of these schools using the Seismic Retrofit
Guidelines 1st Edition (“SRG1”) developed for the BC Ministry of Education. SRG1
is state of the art performance-based seismic assessment tool that can
a. Assign detailed risk ratings to each school block and individual structural
components to help prioritize the upgrading of the various school blocks
and/or identify opportunities for phased retrofits, and
b. Yield more cost-effective seismic upgrading solutions compared to
assessment using NBC 2010.
DNA is very experienced in the application of SRG1 and can carry out further
evaluation of the schools using SRG1 to supplement the findings of this
assessment.
END OF REPORT
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APPENDIX A
Class 4 Cost Estimate Summary
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Description
Built
Floor Area (sf)
Roof
Upper Floor
Main Floor
Walls
Foundations
Miscellaneous
& NonStructural
Additional
Arch/Mech/Ele
c
Hazardous
Materials
Conctractor
Overhead &
Profit
Construction
Contingency
Consultant
Fees
Block Total
Block ($/sf)
School Total
School ($/sf)
August 28, 2013
Block
Seismic Evaluation of Various Yukon Schools - Class 4 Cost Estimate Summary
School
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Kluane Lake
1
Original
1961
6,240
$49,450
$0
$27,140
$25,200
$72,570
$50,000
$40,385
$62,400
$65,429
$65,429
$58,886
$516,889
$83
$516,889
$83
Nelnah Bessie John
1
Original
1961
6,240
$49,450
$0
$27,140
$25,200
$72,570
$50,000
$40,385
$62,400
$65,429
$65,429
$58,886
$516,889
$83
$516,889
$83
1
Original
1963
6,810
$37,550
$0
$0
$180,875
$27,500
$0
$44,267
$68,100
$71,658
$71,658
$64,492
$566,101
$83
2a
Class
1978
6,925
$24,945
$0
$0
$139,350
$0
$0
$29,573
$69,250
$52,624
$52,624
$47,361
$415,727
$60
2b
Arts/Gym
1978
16,122
$97,525
$0
$24,840
$59,150
$41,000
$0
$40,053
$161,220
$84,758
$84,758
$76,282
$669,585
$1,758,009
$48
$42
3
Addition
1993
6570
$26,320
$0
$9,265
$17,150
$0
$4,440
$10,292
$0
$13,493
$13,493
$12,144
$106,597
$16
1
Gym/Office
1954
7,776
$97,180
$61,400
$0
$59,700
$108,000
$96,300
$76,064
$77,760
$115,281 $115,281 $103,753
$910,719
$117
2
Class
1954
12,960
$173,500
$99,500
$0
$258,535 $154,500
$20,000
$127,086 $129,600 $192,544 $192,544 $173,290 $1,521,100
$2,431,819
$117
$117
1
Original
1960
14,765
$418,820
$0
$0
$98,598
$0
$2,500
$93,585
$147,650 $152,231 $152,231 $137,008 $1,202,622
$81
2
Addition
1965
3,900
$35,686
$0
$0
$87,015
$0
$0
$22,086
$39,000
$36,757
$74
3
Addition
1982
9,005
$197,495
$0
$0
$552,932
$0
$0
$135,077
$90,050
$195,111 $195,111 $175,600 $1,541,375
$3,579,058
$105
$171
4
Addition
2001
6,395
$186,427
$0
$0
$47,724
$0
$3,800
$42,831
$63,950
$68,946
$68,946
$62,052
$544,677
$85
1
Original
1958
17,184
$54,820
$24,720
$0
$74,660
$0
$10,000
$29,556
$171,835
$73,118
$73,118
$65,806
$577,634
$34
2
Addition
1972
12,844
$252,290
$0
$0
$0
$0
$0
$45,412
$128,440
$85,228
$85,228
$76,706
$673,305
$52
$2,460,576
$57
3
Addition
1978
13,403
$226,830
$0
$0
$150,090 $149,800
$11,550
$96,889
$130,435 $153,119 $153,119 $137,807 $1,209,637
$93
1
Class
1960
22,580
$183,795
$53,100
$43,930
$119,615
$63,345
$22,500
$87,531
$225,800 $159,923 $159,923 $143,931 $1,263,394
$56
2
Gym
1960
7,285
$0
$0
$11,050
$12,000
$0
$0
$4,149
$72,850
$20,010
$20,010
$18,009
$158,077
$22
$1,538,686
$46
3
Addition
1988
3,415
$8,177
$0
$19,527
$35,166
$0
$0
$11,317
$0
$14,837
$14,837
$13,354
$117,214
$34
1
Original
1950
63,335
$251,880 $276,600 $374,080 $711,250 $780,000
$54,000
$440,606 $633,350 $704,353 $704,353 $633,918 $5,564,390
$88
2
Addition
1954
17,868
$30,000
$64,800
$79,594
$6,671,123
$82
$62
St. Elias Community
Wood Centre
Christ the King
Selkirk
Takhini
$37,200
$37,200
$35,000
$237,990
$36,757
$33,082
$290,384
$178,680 $140,093 $140,093 $126,084 $1,106,733
Note:
1. This cost estimate shall be read in conjunction with DNA's report on the Seismic Evaluation of Various Yukon Schools (August 28, 2013).
2. Costs are based on 2013 Canadian dollars.
3. Costs are based on carrying out the project all at once with no phasing.
4. The cost estimate is an ASTM Class 4 Cost Estimate with an expected accuracy between +30% and ‐20% for a project that is defined up to 15% complete. No drawings are developed as part of this cost estimate.
5. The cost estimate does not include soft costs, such as taxes, moving costs, temporary facilities, loss of use/revenue, etc.
6. Refer to the general report for the Seismic Evaluation of Various Yukon Schools and the individual reports for each school for additional details and information.
August 28, 2013
APPENDIX B
Desktop Study Seismic Screening of Selected Yukon
School Building Sites EBA Engineering Consultants Ltd
DNA 5143/5144
April 2, 2013
Government of Yukon
Property Management Division (W-5)
PO Box 2703
Whitehorse, YT Y1A 2C6
ISSUED FOR USE
EBA FILE: W14103138-01
Via Email: anton.pertschy@gov.yk.ca
Attention:
Anton Pertschy, Project Manager, Highways and Public Works, Yukon
Subject:
Desktop Geotechnical Study for Seismic Evaluation and Bearing Capacity Information
Yukon Schools
1.0
INTRODUCTION
The Government of Yukon (YG) retained EBA Engineering Ltd. operating as EBA, A Tetra Tech Company
(EBA) to provide site classification for seismic site response as per Table 4.1.8.4 A, NBCC 2010 and soil
bearing capacity for eight schools in the Yukon. EBA completed a desktop study using previously collected
data relating to or in the general vicinity of the schools of interest. Mr. Anton Pertschy provided
authorization to proceed by way of email confirmation, dated March 12, 2013. For additional conditions
regarding this report, please refer to EBA’s General Conditions included in Appendix A.
1.1
Scope of Services
EBA’s scope of services for this project was presented to Mr. Anton Pertschy in an email submitted on
March 11, 2013. The scope of services for this project is summarized below:

Completed a desktop study using existing borehole information near the following schools:









2.0
Whitehorse Elementary, Whitehorse
Wood Street Centre, Whitehorse
Christ the King Elementary, Whitehorse
Selkirk Elementary, Whitehorse
Takhini Elementary, Whitehorse
Kluane Lake, Destruction Bay
Saint Elias, Haines Junction
Nelnah Bessie John, Beaver Creek
Prepared a report containing seismic site classification using Table 4.1.8.4 A, NBCC 2010 and
unfactored Ultimate Limit State bearing capacities (ULS) for each school.
SUBSURFACE CONDITIONS AND FOUNDATION ASSUMPTIONS
The subsurface conditions were determined through the interpretation of data from boreholes and testpits
located beneath or near each school. Foundation details were provided by YG in the form of historical
Yukon_Schools_Seismic_and_ULS_Report IFU
EBA Engineering Consultants Ltd. operating as EBA, A Tetra Tech Company
Calcite Business Centre, Unit 6, 151 Industrial Road
Whitehorse, YT Y1A 2V3 CANADA
p. 867.668.3068 f. 867.668.4349
DESKTOP GEOTECHNICAL STUDY FOR SEISMIC EVALUATION, WHITEHORSE AND YUKON SCHOOLS
EBA FILE: W14103138-01 | APRIL 2, 2013 | ISSUED FOR USE
structural and architectural drawings. The assumed subsurface conditions as well as assumed footing sizes
and burial depths are presented in the following subsections.
2.1.1
Table 2.1.1 presents the subsurface conditions in the vicinity of Whitehorse Elementary. The assumed
foundation parameters were as follows:
 0.6 m x 0.6 m x 0.3 m spread footing buried at 0.5 m
 0.6 m x 0.3 m continuous strip footing buried at 0.5 m
Table 2.1.1: Subsurface Soil Conditions near Whitehorse Elementary
Strata Depth Range (m)
Soil Type
1240009-MW02
1240009-MW03
15486-BH01
15486-BH02
Asphalt
0.0 – 0.1
0.0 – 0.1
0.0 – 0.1
0.0 – 0.1
SAND and GRAVEL
0.1 – 3.0
0.1 – 3.5
-
-
SAND – silty
-
-
0.3 – 1.0
0.4 – 0.7
GRAVEL
-
3.5 – 4.4
1.0 – 3.0
0.7 – 4.2
SILT
3.0 – 6.8
4.4 – 6.8
-
4.2 – 4.5
End of Hole
6.8
6.8
3.0
4.5
2.1.2
Table 2.1.2 presents the subsurface conditions in the vicinity of the Wood Street Centre. The assumed
Table 2.1.2: Subsurface Soil Conditions near Wood Street Centre
Soil Type
10153-01
10831-06
GRAVEL
0.0 – 1.0
0.0 – 1.0
Organic SILT
1.0 – 1.1
-
SAND
1.1 – 1.5
1.0 – 1.3
GRAVEL
1.5 – 2.5
-
SILT
2.5 – 7.3
1.3- 6.0
End of Hole
7.3
6.0
2
2.1.3
Table 2.1.3 presents the subsurface conditions in the vicinity of Christ the King Elementary. The assumed
Table 2.1.3: Subsurface Soil Conditions near Christ the King Elementary
Soil Type
W14101227 BH04
W14101227 BH02
ORGANICS
0.0 – 0.1
0.0 – 0.1
SAND and GRAVEL
0.1 – 2.1
0.1 – 2.5
SAND
2.1 – 6.0
2.5 – 7.8
2.1.4
SILT
-
-
SAND
-
-
End of Hole
6.0
7.8
Table 2.1.4 presents the subsurface conditions in the vicinity of Selkirk Elementary. The assumed
Table 2.1.4: Subsurface Soil Conditions near Selkirk Elementary
Soil Type
W14101374 BH12
W14101374 BH13
ORGANICS
-
-
SAND and GRAVEL
0.0 – 3.0
0.0 – 2.5
SAND
-
-
SILT
3.0 – 7.8
2.5 – 9.4
SAND
7.8 – 9.4
-
End of Hole
9.4
9.4
3
2.1.5
Table 2.1.5 presents the subsurface conditions in the vicinity of Takhini Elementary. The assumed
Table 2.1.5: Subsurface Soil Conditions near Takhini Elementary
Soil Type
BST surface
11761 - 01
11761 - 02
10460 - 01
0.0 – 0.1
-
0.0 – 0.1
GRAVEL and SAND
0.1 – 1.2
0.1 – 1.1
-
SAND
1.2 – 2.2
1.1 – 2.0
0.0 – 0.8
2.1.6
SILT
-
-
0.8 – 3.0
End of Hole
2.2
2.0
3.0
Table 2.1.6 presents the subsurface conditions in the vicinity of Kluane Lake School, Destruction Bay. The
assumed foundation parameters were as follows:
Table 2.1.6: Subsurface Soil Conditions near Kluane Lake School, Destruction Bay
Soil Type
10008 - 01
ORGANIC SILT
-
10008 - 02
10008 - 03
0.0 – 0.3
-
GRAVEL and SAND
0.0 – 1.5
0.3 – 1.8
SAND
1.5 – 4.8
1.8 – 6.9
0.0 – 5.5
GRAVEL and SAND
-
-
5.5 – 6.0
ORGANICS
4.8 – 5.5
6.9 – 7.0
-
End of Hole
5.5
7.0
6.0
4
2.1.7
Table 2.1.7 presents the subsurface conditions in the vicinity of Saint Elias, Haines Junction. The assumed
Table 2.1.7: Subsurface Soil Conditions near Saint Elias, Haines Junction
Soil Type
2.1.8
1240021 TP07
1240021 TP08
SAND, Grass and Rootlets
0.0 – 0.6
0.0 – 0.6
SILT (TILL)
0.6 – 6.1
0.6 – 5.5
End of Hole
6.1
5.5
Table 2.1.8 presents the subsurface conditions in the vicinity of Nelnah Bessie John, Beaver Creek. The
assumed foundation parameters were as follows:
Table 2.1.8: Subsurface Soil Conditions near Nelnah Bessie John, Beaver Creek
Soil Type
ORGANICS
3.0
W14101322 TP01
W14101322 TP02
W14101322 TP03
W14101322 TP04
0.0 – 0.1
0.0 – 0.1
0.0 – 0.1
0.0 – 0.1
SILT
0.1 – 0.3
0.1 – 0.3
0.1 – 0.3
0.1 – 0.3
SAND and GRAVEL
0.3 – 2.0
0.3 – 1.0
0.3 – 1.0
0.3 – 3.0
End of Hole
2.0
1.0
1.0
3.0
SEISMIC CLASSIFICATION AND ULS BEARING CAPACITIES
The following Table 3.0 presents a summary of Seismic Classifications as per Table 4.1.8.4.A, NBCC 2010.
The Standard Penetration Test results were determined during the drilling programs or determined from
the subsurface soils encountered at each of the school sites.
5
Table 3.0: Summary of Seismic Classification
3.1
School
Standard Penetration Test (N60)
Seismic Classification
<15
Class E
<15
Class E
<15
Class E
<15
Class E
<15
Class E
15 to 50
Class D
15 to 50
Class D
15 to 50
Class D
Limit States Bearing Resistance
Under Limit State Design (LSD) as per the NBCC 2010, the unfactored Ultimate Limit State (ULS) loading
cases was considered for all of the school foundations. The ULS bearing resistance is the maximum
pressure that the soil can withstand prior to causing a bearing failure. This resistance is highly dependent
on soil properties, footing size and shape, and burial depth.
The geotechnical resistance factors required to calculate the factored foundation resistances are provided
in Table 3.1.
Table 3.1: Geotechnical Resistance Factors – Shallow Foundations
Item
Resistance Factor*
Vertical resistance by semi-empirical analysis using laboratory and in-situ test data
0.5
Sliding: based on friction (c=0)
0.8
* From “User’s Guide – NBCC, Structural Commentaries (Part 4 of Division B)”
3.2
Static Foundation Design – ULS
All of the school foundations are considered shallow foundations (strip and/or spread footings) that are at
a shallow depth below finished exterior grade or on finished grade. The ultimate unfactored bearing
resistance parameters for foundation footings supporting axial compressive loads placed on the grade of
the native material or Engineered Fill compacted to a minimum 98% of maximum dry density are
presented in Table
6
Table 3.2: Summary of Seismic Classification and ULS Values
ULS Bearing Capacity (kPa)
School
Spread Footing
Strip Footing
500-850
300
700-850
500
1200-1450
750
600-1350
N/A
1150
500 - 650
300
200
700
450 - 800
450
300
7
4.0
LIMITATIONS OF REPORT
This report and its contents are intended for the sole use of Government of Yukon and their agents. EBA
Engineering Consultants Ltd. operating as EBA, A Tetra Tech Company, does not accept any responsibility
for the accuracy of any of the data, the analysis, or the recommendations contained or referenced in the
report when the report is used or relied upon by any Party other than Government of Yukon, or for any
Project other than the proposed development at the subject site. Any such unauthorized use of this report
is at the sole risk of the user. Use of this report is subject to the terms and conditions stated in EBA’s
Services Agreement. EBA’s General Conditions are provided in Appendix A of this report.
5.0
CLOSURE
The information presented is believed to be representative of the school sites noted; however, if site
specific information is obtained that differs from that presented herein, EBA should be given the
opportunity to review the seismic site classification and ULS values.
We trust this report meets your present requirements. Should you have any questions or comments,
please contact the undersigned.
Sincerely,
Ian MacIntyre, EIT
Geotechnical Engineer, Arctic Region
Direct Line: 867.668.2071 x254
imacintyre@eba.ca
Kathleen Jarvis, EIT
Geotechnical Engineer, Arctic Region
Direct Line: 867.668.2071 x254
kjarvis@eba.ca
Chad Cowan, P.Eng.
Project Director – Yukon, Arctic Region
Direct Line: 867.668.2071 x229
ccowan@eba.ca
8
APPENDIX A
EBA’S GENERAL CONDITIONS
GENERAL CONDITIONS
GEOTECHNICAL REPORT
This report incorporates and is subject to these “General Conditions”.
1.0
USE OF REPORT AND OWNERSHIP
This geotechnical report pertains to a specific site, a specific
development and a specific scope of work. It is not applicable to
any other sites nor should it be relied upon for types of development
other than that to which it refers. Any variation from the site or
development would necessitate a supplementary geotechnical
assessment.
This report and the recommendations contained in it are intended
for the sole use of EBA’s Client. EBA does not accept any
responsibility for the accuracy of any of the data, the analyses or
the recommendations contained or referenced in the report when
the report is used or relied upon by any party other than EBA’s
Client unless otherwise authorized in writing by EBA.
Any
unauthorized use of the report is at the sole risk of the user.
This report is subject to copyright and shall not be reproduced either
wholly or in part without the prior, written permission of EBA.
Additional copies of the report, if required, may be obtained upon
request.
2.0
ALTERNATE REPORT FORMAT
Where EBA submits both electronic file and hard copy versions of
reports, drawings and other project-related documents and
deliverables (collectively termed EBA’s instruments of professional
service), only the signed and/or sealed versions shall be considered
final and legally binding. The original signed and/or sealed version
archived by EBA shall be deemed to be the original for the Project.
Both electronic file and hard copy versions of EBA’s instruments of
professional service shall not, under any circumstances, no matter
who owns or uses them, be altered by any party except EBA.
EBA’s instruments of professional service will be used only and
exactly as submitted by EBA.
Electronic files submitted by EBA have been prepared and
submitted using specific software and hardware systems. EBA
makes no representation about the compatibility of these files with
the Client’s current or future software and hardware systems.
3.0
ENVIRONMENTAL AND REGULATORY ISSUES
Unless stipulated in the report, EBA has not been retained to
investigate, address or consider and has not investigated,
addressed or considered any environmental or regulatory issues
associated with development on the subject site.
General Conditions - Geotechnical.doc
4.0
NATURE AND EXACTNESS OF SOIL AND
ROCK DESCRIPTIONS
Classification and identification of soils and rocks are based upon
commonly accepted systems and methods employed in
professional geotechnical practice.
This report contains
descriptions of the systems and methods used. Where deviations
from the system or method prevail, they are specifically mentioned.
Classification and identification of geological units are judgmental in
nature as to both type and condition. EBA does not warrant
conditions represented herein as exact, but infers accuracy only to
the extent that is common in practice.
Where subsurface conditions encountered during development are
different from those described in this report, qualified geotechnical
personnel should revisit the site and review recommendations in
light of the actual conditions encountered.
5.0
LOGS OF TESTHOLES
The testhole logs are a compilation of conditions and classification
of soils and rocks as obtained from field observations and
laboratory testing of selected samples. Soil and rock zones have
been interpreted. Change from one geological zone to the other,
indicated on the logs as a distinct line, can be, in fact, transitional.
The extent of transition is interpretive. Any circumstance which
requires precise definition of soil or rock zone transition elevations
may require further investigation and review.
6.0
STRATIGRAPHIC AND GEOLOGICAL INFORMATION
The stratigraphic and geological information indicated on drawings
contained in this report are inferred from logs of test holes and/or
soil/rock exposures. Stratigraphy is known only at the locations of
the test hole or exposure. Actual geology and stratigraphy between
test holes and/or exposures may vary from that shown on these
drawings. Natural variations in geological conditions are inherent
and are a function of the historic environment. EBA does not
represent the conditions illustrated as exact but recognizes that
variations will exist. Where knowledge of more precise locations of
geological units is necessary, additional investigation and review
may be necessary.
GENERAL CONDITIONS
GEOTECHNICAL REPORT
7.0
11.0 DRAINAGE SYSTEMS
PROTECTION OF EXPOSED GROUND
Excavation and construction operations expose geological materials
to climatic elements (freeze/thaw, wet/dry) and/or mechanical
disturbance which can cause severe deterioration.
Unless
otherwise specifically indicated in this report, the walls and floors of
excavations must be protected from the elements, particularly
moisture, desiccation, frost action and construction traffic.
8.0
Where temporary or permanent drainage systems are installed
within or around a structure, the systems which will be installed
must protect the structure from loss of ground due to internal
erosion and must be designed so as to assure continued
performance of the drains. Specific design detail of such systems
should be developed or reviewed by the geotechnical engineer.
Unless otherwise specified, it is a condition of this report that
effective temporary and permanent drainage systems are required
and that they must be considered in relation to project purpose and
function.
SUPPORT OF ADJACENT GROUND AND
STRUCTURES
Unless otherwise specifically advised, support of ground and
structures adjacent to the anticipated construction and preservation
of adjacent ground and structures from the adverse impact of
construction activity is required.
9.0
12.0 BEARING CAPACITY
Design bearing capacities, loads and allowable stresses quoted in
this report relate to a specific soil or rock type and condition.
Construction activity and environmental circumstances can
materially change the condition of soil or rock. The elevation at
which a soil or rock type occurs is variable. It is a requirement of
this report that structural elements be founded in and/or upon
geological materials of the type and in the condition assumed.
Sufficient observations should be made by qualified geotechnical
personnel during construction to assure that the soil and/or rock
conditions assumed in this report in fact exist at the site.
INFLUENCE OF CONSTRUCTION ACTIVITY
There is a direct correlation between construction activity and
structural performance of adjacent buildings and other installations.
The influence of all anticipated construction activities should be
considered by the contractor, owner, architect and prime engineer
in consultation with a geotechnical engineer when the final design
and construction techniques are known.
10.0 OBSERVATIONS DURING CONSTRUCTION
13.0 SAMPLES
Because of the nature of geological deposits, the judgmental nature
of geotechnical engineering, as well as the potential of adverse
circumstances arising from construction activity, observations
during site preparation, excavation and construction should be
carried out by a geotechnical engineer. These observations may
then serve as the basis for confirmation and/or alteration of
geotechnical recommendations or design guidelines presented
herein.
EBA will retain all soil and rock samples for 30 days after this report
is issued. Further storage or transfer of samples can be made at
the Client’s expense upon written request, otherwise samples will
be discarded.
14.0 INFORMATION PROVIDED TO EBA BY OTHERS
During the performance of the work and the preparation of the
report, EBA may rely on information provided by persons other than
the Client. While EBA endeavours to verify the accuracy of such
information when instructed to do so by the Client, EBA accepts no
responsibility for the accuracy or the reliability of such information
which may affect the report.
2
General Conditions - Geotechnical.doc
MODIFIED UNIFIED SOIL CLASSIFICATION
GROUP
SYMBOL
GC
Clayey gravels,
gravel-sand-clay mixtures
SW
Well-graded sands and gravelly
sands, little or no fines
SP
Poorly graded sands and gravelly
sands, little or no fines
SM
Silty sands, sand-silt mixtures
SC
Clayey sands, sand-clay mixtures
ML
Inorganic silts, very fine sands,
rock flour, silty or clayey fine sands
of slight plasticity
MH
Inorganic silts, micaceous or
diatomaceous fine sands or
silts, elastic silts
CL
Inorganic clays of low plasticity,
gravelly clays, sandy clays,
silty clays, lean clays
Inorganic clays of high
plasticity, fat clays
OH
HIGHLY ORGANIC SOILS
PT
Peat and other highly organic
soils
<50
Not meeting both criteria for GW
Atterberg limits
Atterberg limits plot below “A” line plotting in
or plasticity index less than 4
hatched area are
borderline
classifications
Atterberg limits plot above “A” line requiring use of
or plasticity index greater than 7
dual symbols
2
(D30)
CC =
D10 x D60
Atterberg limits
Atterberg limits plot below “A” line plotting in
or plasticity index less than 4
hatched area are
borderline
classifications
Atterberg limits plot above “A” line requiring use of
or plasticity index greater than 7
dual symbols
PLASTICITY CHART
ne
” li
“A
30
CI
20
CL
10
7
4
MH or OH
CL - ML
ML or OL
0
0
10
20
30
2046-11.cdr
40
50
60
70
80
90
100
LIQUID LIMIT
*Based on the material passing the 75 mm sieve
Reference: ASTM Designation D2487, for identification procedure
see D2488. USC as modified by PFRA
OVERSIZE MATERIAL
DEFINING RANGES OF
PERCENTAGE BY MASS OF
MINOR COMPONENTS
PASSING
RETAINED
PERCENTAGE
DESCRIPTOR
75 mm
19 mm
19 mm
4.75 mm
>35 %
“and”
21 to 35 %
“y-adjective”
10 to 20 %
“some”
>0 to 10 %
“trace”
Rounded or subrounded
COBBLES
BOULDERS
75 mm to 300 mm
> 300 mm
Not rounded
SAND
SILT (non plastic)
or
CLAY (plastic)
CH
40
GRAVEL
coarse
medium
fine
Between 1 and 3
Not meeting both criteria for SW
SOIL COMPONENTS
coarse
fine
Greater than 6
CU = D60/D10
Equation of “A” line: P I = 0.73 (LL - 20)
Organic clays of medium
to high plasticity
SIEVE SIZE
Between 1 and 3
Soils passing 425 mm
Organic silts and organic silty clays
of low plasticity
Liquid limit
(D30)
D10 x D60
50
OL
FRACTION
Greater than 4
2
CC =
For classification of fine-grained soils and fine fraction of coarse-grained soils.
PLASTICITY INDEX
<50
>50
<30
30-50
CH
CU = D60/D10
60
>50
>50
SILTS
Liquid limit
Liquid limit
CI
Inorganic clays of medium
plasticity, silty clays
GW, GP, SW, SP
GM, GC, SM, SC
Borderline Classification
requiring use of dual symbols
Silty gravels,
gravel-sand-silt mixtures
Less than 5% Pass 75 mm sieve
More than 12% Pass 75 mm sieve
5% to 12% Pass 75 mm sieve
GRAVELS
WITH
FINES
GM
Classification on basis of percentage of fines
CLEAN
GRAVELS
Poorly graded gravels and gravelsand mixtures, little or no fines
CLEAN
SANDS
GP
SANDS
WITH
FINES
GRAVELS
50% or more of coarse fraction
retained on 4.75 mm sieve
SANDS
More than 50% of coarse
fraction passes 4.75 mm sieve
LABORATORY CLASSIFICATION CRITERIA
Well-graded gravels and gravelsand mixtures, little or no fines
ORGANIC SILTS
AND CLAYS
CLAYS
TYPICAL
DESCRIPTION
GW
Above “A” line on plasticity
chart negligible organic content
FINE-GRAINED SOILS (by behavior)
50% or more passes 75 mm sieve*
COARSE-GRAINED SOILS
More than 50% retained on 75 mm sieve*
MAJOR DIVISION
4.75 mm
2.00 mm
425 mm
2.00 mm
425 mm
75 mm
75 mm
as above but
by behavior
ROCK FRAGMENTS
ROCKS
>75 mm
> 0.76 cubic metre in volume
KLUANE LAKE ELEMENTARY SCHOOL
SEISMIC EVALUATION
August 28, 2013
Note: This school report is to be read in conjunction with the general report for all eight Yukon schools.
DNA 5143/5144
August 28, 2013
TABLE OF CONTENTS
1.0
2.0
3.0
4.0
DESCRIPTION OF SCHOOL
BLOCK ONE – 1961 ORIGINAL CONSTRUCTION
FINDINGS
COST ESTIMATE SUMMARY
3
3
5
6
APPENDICES
Appendix A
Appendix B
Appendix C
DNA 5143/5144
Block Plan
Photographs
NRC Guidelines Evaluation Statements for the Basic Building
System
2
1.0
August 28, 2013
Kluane Lake Elementary School was originally constructed in 1961 as a small one-storey
structure with a partial basement. In the early 1970s, there were some non-structural
renovations carried out. In plan, the school is approximately 40 ft x 77 ft. There is only one
Block to consider for evaluation purposes.
2.0
The roof structure consists of 1” thick horizontal shiplap sheathing on 4:12 dimensional
wood trusses spaced at 2 ft on centre. The underside of the dimensional lumber ceiling
joists may be sheathed with 5/16” plywood, although this was not confirmed on site.
The Main Floor structure consists of 5/16” plywood on 1” thick diagonal shiplap sheathing
on 3x14 Fir floor joists spaced at 16” on centre. The floor joists are supported by 10” thick,
unreinforced concrete foundation walls around the perimeter of a partial basement below.
They are supported by a post and beam bearing line on pad footings in the middle of the
basement.
Above the Main Floor, the roof structure is supported around the perimeter by 38x140
wood stud walls sheathed with horizontal shiplap on the outside.
On all four sides of the school, there are canopies over top of the entrances/exists. There’s
also a brick chimney in the middle of the school.
Item
Seismic Deficiency
Retrofit Concept
2.1
The horizontal shiplap roof diaphragm
has inadequate strength and stiffness.
Install plywood sheathing on top of the
existing shiplap.
2.2
Existing 2x6 wall double top plates
constructed using conventional nailing
patterns have inadequate tension
strength to act as diaphragm chords.
Install continuous light gauge strap ties
on top of the plywood sheathing during
roof diaphragm upgrade.
2.3
In-plane load paths between the roof
diaphragm
and
the
wood-frame
shearwalls are inadequate.
Install blocking between roof trusses
above shearwalls below, and connect
to the roof diaphragm and shearwall
with Simpson A35 angles.
Roof
Main Floor
2.4
In-plane anchorage of the floor
diaphragm to concrete foundation walls
is inadequate.
DNA 5143/5144
Install Simpson UFP plates between the
existing sill plate and the top of the
concrete foundation wall.
Increase
connections between the floor framing
and the sill plate.
3
August 28, 2013
Item
Seismic Deficiency
Retrofit Concept
2.5
The connection between the floor
diaphragm and the top of the concrete
wall is inadequate for out-of-plane
forces due to seismic earth pressures
against the foundation wall.
Install
Simpson A35 angles to reinforce the
connection between the floor joists and
the sill plate.
There is inadequate shear strength in
the walls in the long direction of the
building.
At the front and back of the building,
infill windows at each end of the
building, and install new plywood
shearwalls.
2.7
On all four sides of the building, in-plane
load paths are inadequate at the top
and bottom of the existing walls.
Locally remove siding on the outside of
the building to expose the base of the
wood frame walls and the top of the
concrete walls. Install plywood sheets
over the existing framing to reinforce the
connection
between
the
wood
shearwalls and the sill plate across the
floor assembly.
Upgrade sill plate
connections from the inside of the
building using Simpson UFP plates, as
described in the Main Floor Diaphragm
section. Upgrade connections to the
Roof diaphragm as described in that
section.
2.8
Overturning restraint of existing wood
shearwalls is inadequate.
Install
new
Simpson
holdowns
connected to the existing concrete
foundation wall at each end of wood
shearwalls.
Walls
2.6
Foundations
2.9
Unreinforced concrete foundation walls
have inadequate bending strength for
seismic-induced earth pressures.
Expose the interior side of the concrete
foundation wall. Install structural steel
back-up supports on the inside of the
wall.
Miscellaneous and Non-Structural
2.10
Roof canopies over entrances/exists to
the building are a falling hazard.
Upgrade connections of primary
framing members to each other and to
the main building structure.
2.11
Concrete staircase walls at the front and
rear entrances to the building are
unreinforced.
Demolish existing concrete stair and
rebuild in wood frame or reinforced
concrete.
DNA 5143/5144
4
August 28, 2013
Item
Seismic Deficiency
Retrofit Concept
2.12
The brick chimney is a falling hazard
and insufficiently restrained.
Deconstruct chimney and replace with a
new wood frame chase and metal flue.
Hazardous Materials
2.13
There is asbestos board and vermiculite
tile in the Furnace Room. Hazardous
building materials may also exist in other
building components.
3.0
FINDINGS
Retain a hazardous materials consultant
to carry out a review on site.
Remove/abate hazardous
prior to construction.
materials
The seismic deficiencies in this school can be summarized as follows:
 The roof diaphragm has inadequate strength, chords and load paths to perimeter
walls.
 The perimeter walls have inadequate strength and stiffness and load path
connections.
 The unreinforced concrete foundation walls do not have sufficient strength to resist
seismic earth pressures.
 The brick chimney and entry canopies are falling hazards.
 The unreinforced supports for the concrete stairs at the entrances are hazardous.
 Hazardous building materials that exist in this Block should be removed/abated
DNA 5143/5144
5
4.0
August 28, 2013
The cost estimate to retrofit the seismic deficiencies identified in this report is summarized
below:
Kluane Lake Elementary Seismic Upgrading
Class 4 Cost Estimate
Item
Block One
Construction Year
1961
Description
Original
Total Area
6240 sf
Roof7
$49,450
Main Floor
7
$27,140
7
Walls
$25,200
Foundations7
$72,570
7
$50,000
Subtotal 1
$224,360
Additional Arch (10%), Mech (5%), Elec (3%)
$40,385
Hazardous Materials ($10/sf)
$62,400
Subtotal 2
$327,145
Contractor Overhead and Profit (20%)
$65,429
Construction Contingency (20%)
$65,429
Consultant Fees (15%)
Total
6
$58,886
$516,889
$83 / sf
Note:
1. This cost estimate shall be read in conjunction with DNA’s report
on the Seismic Evaluation of Various Yukon Schools (August 28,
2013).
3. Costs are based on carrying out the project all at once with no
phasing.
4. The cost estimate is an ASTM Class 4 Cost Estimate with an
expected accuracy between +30% and -20% for a project that is
defined up to 15% complete. No drawings are developed as part
of this cost estimate.
5. The cost estimate does not include soft costs, such as taxes,
moving costs, temporary facilities, loss of use/revenue, etc.
6. Consultant fees are calculated as a percentage of the subtotal of
all elements except the construction contingency.
7. Refer to retrofit concepts presented in this school report.
DNA 5143/5144
6
APPENDIX A
Block Plan
DNA 5143/5144
August 28, 2013
APPENDIX B
Photographs
DNA 5143/5144
August 28, 2013
Exterior elevation
Exterior canopy
DNA 5143/5144
August 28, 2013
Exterior canopy
Chimney at exterior
DNA 5143/5144
August 28, 2013
Chimney in Basement
DNA 5143/5144
August 28, 2013
Roof framing in Attic
Basement room
DNA 5143/5144
August 28, 2013
Main Floor classroom
DNA 5143/5144
August 28, 2013
August 28, 2013
APPENDIX C
NRC Guidelines Evaluation Statements for the Basic
Building System
DNA 5143/5144
NELNAH BESSIE JOHN
SEISMIC EVALUATION
August 28, 2013
DNA 5143/5144
NELNAH BESSIE JOHN
August 28, 2013
TABLE OF CONTENTS
1.0
2.0
3.0
4.0
FINDINGS
3
3
5
6
APPENDICES
Appendix A
Appendix B
Appendix C
DNA 5143/5144
Block Plan
Photographs
System
2
NELNAH BESSIE JOHN
1.0
August 28, 2013
Nelnah Bessie John was originally constructed in 1961 as a small one-storey structure with
a partial basement. In the early 1970s, there were some non-structural renovations carried
out. In plan, the school is approximately 40 ft x 77 ft. There is only one Block to consider
for evaluation purposes.
2.0
The roof structure consists of 1” thick horizontal shiplap sheathing on 4:12 dimensional
wood trusses spaced at 2 ft on centre. The underside of the dimensional lumber ceiling
joists may be sheathed with 5/16” thick plywood, although this wasn’t confirmed on site.
The Main Floor structure consists of 5/16” plywood on 1” thick diagonal shiplap sheathing
on 3x14 Fir floor joists spaced at 16” on centre. The floor joists are supported by 10” thick,
unreinforced concrete foundation walls around the perimeter of a partial basement below.
They are supported by a post and beam bearing line on pad footings in the middle of the
basement.
Above the Main Floor, the roof structure is supported by 38x140 wood stud wall sheathed
with horizontal shiplap on the outside.
On all four sides of the school, there are canopies over top of the entrances/exists. There’s
also a brick chimney in the middle of the school.
Item
Seismic Deficiency
Retrofit Concept
2.1
has inadequate strength and stiffness.
existing shiplap.
2.2
Existing 2x6 wall double top plates
constructed using conventional nailing
patterns have inadequate tension
strength to act as diaphragm chords.
Install continuous light gauge strap ties
on top of the plywood sheathing during
roof diaphragm upgrade.
2.3
diaphragm and the wood-frame
with Simpson A35 angles.
Roof
Main Floor
2.4
In-plane anchorage of
diaphragm to concrete
walls is inadequate
DNA 5143/5144
the floor
foundation
Increase
connections between the floor framing
and the sill plate.
3
NELNAH BESSIE JOHN
August 28, 2013
Item
Seismic Deficiency
Retrofit Concept
2.5
The connection between the floor
diaphragm and the top of the concrete
wall is inadequate for out-of-plane
forces due to seismic earth pressures
against the foundation wall.
Install
Simpson A35 angles to reinforce the
connection between the floor joists and
the sill plate.
the walls in the long direction of the
building.
At the front and back of the building,
infill windows at each end of the
building, and install new plywood
shearwalls.
2.7
On all four sides of the building, inplane load paths are inadequate at the
top and bottom of the existing walls.
wood frame walls and the top of the
concrete walls. Install plywood sheets
over the existing framing to reinforce the
connection
between
the
wood
shearwalls and the sill plate across the
floor assembly.
Upgrade sill plate
connections from the inside of the
section.
2.8
Install
new
Simpson
holdowns
shearwalls.
Walls
2.6
Foundations
2.9
Unreinforced concrete foundation walls
have inadequate bending strength for
seismic-induced earth pressures.
Expose the interior side of the concrete
foundation wall. Install structural steel
back-up supporst on the inside of the
wall.
2.10
Roof canopies over entrances/exists to
the building are a falling hazard.
Upgrade connections of primary
framing members to each other and to
the main building structure.
2.11
Concrete staircase walls at the front
and rear entrances to the building are
unreinforced.
Demolish existing concrete stair and
rebuild in wood frame or reinforced
concrete.
DNA 5143/5144
4
NELNAH BESSIE JOHN
August 28, 2013
Item
Seismic Deficiency
Retrofit Concept
2.12
and insufficiently restrained.
Deconstruct chimney and replace w/ a
new chimney.
Hazardous Materials
2.13
3.0
There is asbestos board and
vermiculite tile in the Furnace Room.
Hazardous building materials may also
exist in other building components.
materials
FINDINGS
The seismic deficiencies in this school can be summarized as follows:
 The roof diaphragm has inadequate strength, chords and load paths to perimeter
walls.
 The perimeter walls have inadequate strength and stiffness and load path
connections.
 The unreinforced concrete foundation walls do not have sufficient strength to resist
 The brick chimney and entry canopies are falling hazards.
 The unreinforced supports for the concrete stairs at the entrances are hazardous.
 Hazardous building materials that exist in this Block should be removed/abated
DNA 5143/5144
5
NELNAH BESSIE JOHN
4.0
August 28, 2013
below:
Nelnah Bessie John Seismic Upgrading
Item
Block One
Construction Year
1961
Description
Original
Total Area
6240 sf
Roof7
$49,450
Main Floor
7
$27,140
7
Walls
$25,200
Foundations7
$72,570
7
$50,000
Subtotal 1
$224,360
$40,385
$62,400
Subtotal 2
$327,145
$65,429
$65,429
Total
6
$58,886
$516,889
$83 / sf
Note:
1. This cost estimate shall be read in conjunction with DNA’s report
on the Seismic Evaluation of Various Yukon Schools (August 28,
2013).
3. Costs are based on carrying out the project all at once with no
phasing.
4. The cost estimate is an ASTM Class 4 Cost Estimate with an
expected accuracy between +30% and -20% for a project that is
defined up to 15% complete. No drawings are developed as part
of this cost estimate.
5. The cost estimate does not include soft costs, such as taxes,
moving costs, temporary facilities, loss of use/revenue, etc.
6. Consultant fees are calculated as a percentage of the subtotal of
all elements except the construction contingency.
7. Refer to the retrofit concepts presented in this report.
DNA 5143/5144
6
NELNAH BESSIE JOHN
APPENDIX A
Block Plan
DNA 5143/5144
August 28, 2013
NORTH
NELNAH BESSIE JOHN
APPENDIX B
Photographs
DNA 5143/5144
August 28, 2013
NELNAH BESSIE JOHN
Exterior elevation
Exterior elevation
DNA 5143/5144
August 28, 2013
NELNAH BESSIE JOHN
Exterior concrete foundation wall crack at corner
Crack in exterior concrete stair
DNA 5143/5144
August 28, 2013
NELNAH BESSIE JOHN
Exterior canopy
DNA 5143/5144
August 28, 2013
NELNAH BESSIE JOHN
Exterior canopy
Chimney at roof
DNA 5143/5144
August 28, 2013
NELNAH BESSIE JOHN
Basement room
Main Floor classroom
DNA 5143/5144
August 28, 2013
NELNAH BESSIE JOHN
Main Floor corridor
DNA 5143/5144
August 28, 2013
NELNAH BESSIE JOHN
Main Floor framing at wall
Chimney in Basement
DNA 5143/5144
August 28, 2013
NELNAH BESSIE JOHN
August 28, 2013
APPENDIX C
Building System
DNA 5143/5144
ST. ELIAS COMMUNITY SCHOOL
SEISMIC EVALUATION
August 28, 2013
DNA 5143/5144
August 28, 2013
TABLE OF CONTENTS
1.0
2.0
3.0
4.0
5.0
6.0
BLOCK TWO – 1978 ADDITIONS
BLOCK THREE – 1993 ADDITION
FINIDINGS
3
3
5
10
11
12
APPENDICES
Appendix A
Appendix B
Appendix C
DNA 5143/5144
Block Plan
Photographs
System
2
1.0
August 28, 2013
St. Elias Community School was originally constructed in 1963 as a one-storey wood-frame
structure with a crawl space. In 1978, there were two additions: one to the north and one
to the west of the existing school. In 1993, there was another addition to the west. There
are three Blocks to consider for evaluation purposes.
2.0
The roof structure consists of 12.5 mm T&G plywood on 38x89 purlins at 400 mm on
centre and wood trusses at 1830 mm on centre. The underside of the trusses is sheathed
with 9.5 mm plywood on strapping.
The Main Floor structure consists of 18.5 mm T&G plywood on 38x184 Fir floor joists
spaced at 400 mm on centre. The floor joists are supported by 200 mm thick, reinforced
concrete foundation walls around the perimeter of a crawl space and by wood stud pony
walls on reinforced concrete strip footings within the crawl space.
Above the Main Floor, the roof structure is supported by 2x6 wood stud walls, which are
sheathed with 12.5 mm plywood on the perimeter.
Item
Seismic Deficiency
Retrofit Concept
Fastening details of the plywood roof
diaphragm are unknown. At the step
in the roof, there is a discontinuity in
the roof diaphragm due to lack of
adequate load paths between the two
roof levels, resulting in inadequate
diaphragm strength and stiffness.
Introduce a new shearwall at the step
in the roof to reduce the span of the
diaphragm and the demand on the
perimeter shearwalls. Upgrade the
load paths between the roof
diaphragm and the new shearwall.
Roof
2.1
2.2
Existing 2x6 wall double top plates in
the long direction are constructed
using conventional nailing patterns and
have inadequate tension strength to
act as diaphragm chords.
2.3
diaphragm and the wood-frame
Introduce a new shearwall at the step
in the roof to reduce the span of the
diaphragm and the demand on the
diaphragm chords.
In the long direction of the lower roof
area, Install continuous light gauge
strap ties on the sides of the walls at
the double top plate level.
with light gauge hardware.
Main Floor
2.4
The main floor diaphragm has
inadequate capacity due to its span.
DNA 5143/5144
Introduce a new shearwall in the
interior of the building in the Crawl
Space to reduce the diaphragm span.
3
Item
August 28, 2013
Seismic Deficiency
Retrofit Concept
2.5
There are no interior shearwalls within
the Crawl Space.
In the N-S direction, install new
plywood shearwalls at the location of
the step in the roof above. Upgrade
connections to the roof and floor
diaphragms and to the foundation.
2.6
In both directions, there is inadequate
shear strength in the perimeter walls.
Also, the nailing of the existing
plywood wall sheathing on the exterior
of the building is unknown.
Upgrade existing solid perimeter
walls. Install blocking at panel joints
and renail or replace existing
plywood. Install a continuous light
gauge metal strap on the underside of
the windows.
2.7
top and bottom of the existing walls.
Locally remove siding on the outside
of the building to expose the base of
the wood frame walls and the top of
the concrete walls. Install plywood
sheets over the existing framing to
reinforce the connection between the
wood shearwalls and the sill plate
across the floor assembly. Upgrade
sill plate connections from the inside
of the building in the north-south
direction using Simpson UFP plates.
Upgrade connections to the Roof
diaphragm as described in that
section.
2.8
Install new Simpson holdowns
shearwalls.
Walls
Foundations
2.9
At the location of the new N-S
shearwall in the Crawl Space, the
overturning capacity of the existing
footings is inadequate.
Install a mass concrete footing around
existing footings at the ends of the
new Crawl Space shearwalls.
2.10
There’s a vertical irregularity in this
Block as a result of the two different
roof levels.
DNA 5143/5144
When installing continuous strap ties
on the sides of the perimeter wall
double top plates below the lower
roof in the long direction of the
building, continue installing the strap
tie at that same level on the walls
supporting the upper roof.
4
Item
2.11
3.0
Seismic Deficiency
Hazardous building materials may exist
in certain building components.
August 28, 2013
Retrofit Concept
Retain
a
hazardous
materials
consultant to carry out a review on
site.
Remove/abate hazardous materials
BLOCK TWO – 1978 ADDITIONS
There were two additions built in 1978. Another classroom wing was added to the west of
the existing building, and a gym and arts wing was added to the north of the existing
building.
The roof structure of the western classroom wing and the arts wing consists of 1/2"
plywood on wood gangnail trusses at 2 ft on centre. The wood trusses are supported at
perimeter and corridor walls. The underside of the trusses is sheathed with 1/2" drywall
over a suspended ceiling.
The roof structure of the Gym and Stage consists of 3/4" plywood on exposed engineered
TJM and TJL trusses spaced at 800mm and 1200 mm on centre, respectively.
The Main Floor structure consists of 3/4" plywood on 2x10 floor joists spaced at 16” on
centre. The floor joists are supported by 8” thick, reinforced concrete foundation walls
around the perimeter of a crawl space below. The floor joists are supported by wood stud
pony walls on strip footings within the crawl space.
Above the Main Floor, the roof structure is supported by 2x6 wood stud walls sheathed
with 1/2" plywood on the exterior. Around the Gym, the walls are built with 2x8 studs.
DNA 5143/5144
5
Item
Seismic Deficiency
August 28, 2013
Retrofit Concept
Roof – Classroom Wing
At the connection of the Classroom
Wing to the existing 1963 building, load
paths are inadequate between the roof
and the shearwalls below.
3.1
Load path connections are inadequate
between the Block 2 roof and the
shearwalls shared with Blocks 2 and 3.
3.2
Existing perimeter wall double top
plates constructed using conventional
nailing patterns have inadequate
tension strength to act as diaphragm
chords for N-S loading.
Install sheathed stud walls in the roof
space to connect the roof diaphragm to
the shearwalls below.
Upgrade load path connections
between the roof and the shearwalls.
Install blocking between existing
outriggers on top of the wood
shearwall.
Use framing clips to
upgrade
connections
from
roof
diaphragm to shearwall.
Remove exterior soffit and wall finishes
at top of wall, and install continuous
light gauge metal strap ties on outside
of existing double top plates. Or, install
strap ties on top of the roof plywood
sheathing during roof replacement.
Walls – Classroom Wing
3.3
3.4
3.5
The nailing of the existing plywood wall
sheathing on the exterior of the building
is unknown.
Expose the exterior side of the
structural sheathing for assessment.
Or, upgrade walls from the inside of the
building.
In both directions, there is inadequate
shear strength in the perimeter walls,
based on assumed construction details.
Upgrade existing solid perimeter wall
segments. Remove exterior wall
finishes, install new blocking at all panel
edges
where
missing,
and
renail/replace
existing
plywood
sheathing.
bottom of the existing shearwalls.
wood frame shearwalls and the top of
the concrete walls. Install plywood
sheets over the existing framing to
reinforce the connection between the
wood shearwalls and the sill plate
across the floor assembly. Upgrade sill
plate connections from the inside of the
section.
DNA 5143/5144
6
August 28, 2013
Item
Seismic Deficiency
Retrofit Concept
3.6
Install
new
Simpson
holdowns
shearwalls.
Foundations – Classroom Wing
3.7
No upgrades required.
Miscellaneous and Non-Structural – Classroom Wing
Hire a hazardous materials consultant
to carry out a review of the school
facility.
3.8
Any hazardous building materials
affected by the upgrade will have to be
removed prior to construction.
Roof – Arts/Gym Wing
3.9
There are two steps in the roof, and
there is inadequate shear transfer load
paths between the lower roof and
upper roof.
Install blocking between outriggers at
the upper roof level, and connect to
roof diaphragm above and shearwall
between roof levels. At the lower roof
level, upgrade the connection of the
roof diaphragm to the wood transition
shearwall.
Install new drag struts at roof level or
upgrade connections at existing drag
strut discontinuities on all sides of the
Gym including the Stage.
3.10
There is inadequate drag strut
anchorage between the Gym roof and
the surrounding roofs.
3.11
Along the west wall of the Gym, there
are inadequate load paths between the
lower roof diaphragm and the Gym wall.
Upgrade load path connections.
3.12
At canopy locations, there are
inadequate
connections
between
rafters and roof beams.
Upgrade connections.
DNA 5143/5144
Along the four sides of the Gym, and
parallel to the Stage wall, install
continuous drag struts. Reinforce
trusses to act as drag struts and utilize
existing gym double top plates where
possible, upgrading their connections
to each other.
7
August 28, 2013
Item
Seismic Deficiency
Retrofit Concept
3.13
Roof trusses are not stable under lateral
loading.
Install bracing systems to stabilize the
trusses.
Main Floor – Arts/Gym Wing
3.14
The
Main
Floor
diaphragm
is
inadequate as it is very large with no
interior shearwalls, and it is supporting
lateral loads from the interior Gym walls
above.
3.15
At the south end of the shop, the floor
diaphragm is discontinuous at the
dropped floor area.
Install new shearwalls within the Crawl
Space, directly underneath the north
and west Gym walls, to reduce the size
of the Main Floor diaphragm.
Along the north and west Gym walls
and along the Stage wall, install
continuous drag struts at the main floor
diaphragm level.
Install blocking
between floor joists plus a continuous
light gauge metal strap.
Splice adjacent floor joists together by
upgrading their connections.
Walls – Arts/Gym Wing
3.16
3.17
Plywood shearwalls around the Gym
are discontinuous at the Main Floor
level.
shearwalls is inadequate on the north
side of the Shop, the east and west
side of the Gym, and at the Stage walls.
Install plywood shearwalls
Crawl Space on the north
sides of the Gym and at the
directly underneath the
above.
within the
and west
Stage wall
shearwalls
Above the Main Floor, install 4 new
holdowns connected to the existing
concrete foundation wall, and install 6
new holdown connections across the
main floor assembly to the shearwalls
below.
At the foundation level within the Crawl
Space, install 6 holdowns to connect
the Crawl Space shearwalls to the
existing concrete foundations.
Foundations – Arts/Gym Wing
3.18
Existing foundations under the Stage
walls do not have adequate overturning
capacity.
DNA 5143/5144
Install enlarged footings.
8
Item
Seismic Deficiency
August 28, 2013
Retrofit Concept
Miscellaneous and Non-Structural – Arts/Gym Wing
3.19
DNA 5143/5144
materials
9
4.0
August 28, 2013
The roof structure consists of 12.5 mm plywood on wood trusses at 610 mm on centre.
The trusses are supported by wood stud walls around the perimeter of the building and by
corridor stud walls and beams within the interior. Perimeter walls are sheathed with 9.5
mm OSB above the Main Floor.
The Main Floor structure consists of 18.5 mm plywood on wood floor trusses. The floor
joists are supported around the perimeter by a preserved wood foundation consisting of
38x140 studs and 12.5mm plywood sheathing on continuous strip footings. The floor joists
are supported by wood stud pony walls on strip footings within the crawl space.
Item
Seismic Deficiency
Retrofit Concept
Roof
4.1
There are inadequate connections
between the Block 3 roof and the Block
2 roof/wall.
Upgrade in-plane and out-of-plane
connections
between
the
roof
diaphragm and the 1978 Addition end
wall.
Install a drag strut connecting the Block
3 roof to the north Block 2 shearwall.
4.2
Canopy framing
inadequate.
connections
are
Replace existing elevated post bases.
Add connections at joist-to-beam and
beam-to-wall.
Main Floor
4.3
Connections between the main floor
diaphragm and the existing concrete
foundation walls are inadequate.
Upgrade connections between the main
floor diaphragm and the existing
concrete foundation walls.
Install a drag strut connecting the Block
3 roof to the north Block 2 shearwall to
reduce the load on the Block 3
shearwalls.
Walls
4.4
Foundations
4.5
Load paths between preserved wood
foundations and concrete footings are
unknown and assumed to be
inadequate.
Remove wall finishes on the interior side
of the Crawl Space to expose the base
of the structural wall. Install new bolts
between the sill plates and the concrete
footings.
4.6
Tall load-bearing pony walls in the Crawl
Space are unbraced.
DNA 5143/5144
Install solid blocking and lateral bracing
for all such pony walls.
10
5.0
August 28, 2013
FINDINGS
There are several seismic deficiencies in the original construction of the school:
 In Block One, the roof diaphragm has inadequate strength and stiffness
due to its span and the lack of shear transfer at the step in the roof. There
are also insufficient diaphragm chords and load path connections. There
is inadequate strength and stiffness in the wall framing, and the main floor
diaphragm span is too large to transfer lateral loads to perimeter
foundation walls.
 In the Classroom Wing of Block Two, the connection to Block One is
inadequate for the transfer of shared lateral loads. Some walls do not have
adequate strength and stiffness, and load path connections do not meet
requirements.
 In the Arts/Gym Wing of Block Two, there is inadequate shear transfer at
steps in the roof diaphragm, and there are inadequate drag struts and load
path connections to tie the lower roof to the Gym roof. Roof truss framing
is potentially unstable under lateral loading. Interior gym shearwalls do not
continue to the foundations, while the main floor diaphragm is inadequate
for transferring shearwall loads from above. Canopy connections require
upgrading.
 Hazardous building materials that exist in this Block should be
removed/abated prior to construction.
DNA 5143/5144
11
6.0
August 28, 2013
below:
St. Elias Community School Seismic Upgrading
Item
Block 1
Block 2
Classroom
Block 2
Arts/Gym
Block 3
Total
Construction Year
1963
1978
1978
1993
-
Description
Original
Class
Arts/Gym
Addition
-
Total Area
6810 sf
6925 sf
16,122 sf
6570 sf
36427 sf
Roof7
$37,550
$24,945
$97,525
$26,320
$186,340
$0
$0
$24,840
$9,265
$34,105
Walls
$180,875
$139,350
$59,150
$17,150
$396,525
Foundations7
$27,500
$0
$41,000
$0
$68,500
Miscellaneous and
Non-Structural7
$0
$0
$0
$4,440
$4,440
Subtotal 1
$245,925
$164,295
$222,515
$57,175
$689,910
Additional Arch (10%),
Mech (5%), Elec (3%)
$44,267
$29,573
$40,053
$10,292
$124,185
Hazardous Materials
($10/sf)
$68,100
$69,250
$161,220
$0
$298,570
Subtotal 2
$358,292.00
$263,118
$423,788.00
$67,467.00
$1,112,665
Contractor Overhead
and Profit (20%)
$71,658
$52,624
$84,758
$13,493
$222,533
Construction
Contingency (20%)
$71,658
$52,624
$84,758
$13,493
$222,533
Consultant Fees
(15%)6
$64,492
$47,361
$76,282
$12,144
$200,279
Total
$566,101
$83 / sf
$415,727
$60 / sf
$669,585
$42 / sf
$106,597
$16 / sf
$1,758,010
$48 / sf
Main Floor
7
7
Note:
1. This cost estimate shall be read in conjunction with DNA’s report on the Seismic Evaluation of Various
Yukon Schools (August 28, 2013).
4. The cost estimate is an ASTM Class 4 Cost Estimate with an expected accuracy between +30% and 20% for a project that is defined up to 15% complete. No drawings are developed as part of this cost
estimate.
5. The cost estimate does not include soft costs, such as taxes, moving costs, temporary facilities, loss of
use/revenue, etc.
6. Consultant fees are calculated as a percentage of the subtotal of all elements except the construction
contingency.
DNA 5143/5144
12
APPENDIX A
Block Plan
DNA 5143/5144
August 28, 2013
APPENDIX B
Photographs
DNA 5143/5144
August 28, 2013
Block 1 Elevation
Block 2 Arts/Gym Elevation
DNA 5143/5144
August 28, 2013
Block 2 Classroom Elevation
Block 3 Elevation
DNA 5143/5144
August 28, 2013
Typical canopy
DNA 5143/5144
August 28, 2013
Block 2 Gym interior
Block 1 roof framing in Attic
DNA 5143/5144
August 28, 2013
Block 1 roof framing in Attic
Block 2 Arts/Gym roof framing in Attic
DNA 5143/5144
August 28, 2013
Corridor
Block 2 floor framing in Crawl Space
DNA 5143/5144
August 28, 2013
Block 3 Crawl Space
Block 3 Crawl Space
DNA 5143/5144
August 28, 2013
August 28, 2013
APPENDIX C
NRC Guidelines
Evaluation Statements for the Basic Building System
DNA 5143/5144
WOOD
W
STREE
S
ET CENTRE
SE
EISMIC EV
VALUATION
OF
F VARIOU
US YUKO
ON SCHOOLS
Aug
gust 28, 2013
port is to be read in conjunction wiith the general re port for all eight Y
Yukon schools.
Note:: This school rep
DNA
A 5143/5144
4
WOOD STREET CENTRE
August 28, 2013
TABLE OF CONTENTS
1.0
2.0
3.0
4.0
5.0
BLOCK ONE – GYM/OFFICE
BLOCK TWO – CLASSROOM
FINDINGS
3
3
6
10
11
APPENDICES
Appendix A
Appendix B
Appendix C
DNA 5143/5144
Block Plan
Photographs
System
2
WOOD STREET CENTRE
1.0
August 28, 2013
Wood Street Centre was originally constructed in 1954 as a two-storey structure with a
classroom wing to the east and a gym/office wing to the west. In plan, the school is
approximately 72 ft x 163 ft. For evaluation purposes, the school is split into two blocks.
2.0
BLOCK ONE – GYM/OFFICE
The roof structure consists of 2” T&G decking bolted to 30” deep open web steel joists
spaced at 5’-0” on centre. There is a 4” thick suspended slab over the stairwell.
The Upper Floor structure consists of a 2 1/2" reinforced concrete slab on steelcrete on
18” deep open web steel joists spaced at 2’-4” on centre.
At the Main Floor level, there is a 4” slab-on-grade. The foundations around the perimeter
of the block include 12” thick, unreinforced concrete foundation walls on 12” deep x 24”
wide concrete strip footings.
The floor and roof structures are supported by reinforced concrete walls, beams and
columns around the perimeter, and there is a concrete beam/column line in the interior of
the block below the Upper Floor.
Item
Seismic Deficiency
Retrofit Concept
2.1
The 2” wood decking diaphragm has
inadequate strength and stiffness for
supporting the concrete walls.
Install new plywood sheathing on top of
plank decking. Re-roofing is required.
2.2
At the stairwell (SW) location, there is
a re-entrant corner in the wood
diaphragm
without
adequate
reinforcing.
Install light gauge steel straps nailed on
top of the new plywood sheathing in two
orthogonal directions at the re-entrant
corner of the roof diaphragm.
2.3
In-plane load path connections
between the roof diaphragm and
perimeter walls are inadequate.
Install new steel angles connected to the
underside of the plank decking and to
the inside of the concrete perimeter
beam.
Remove and replace ceiling
adjacent to wall.
2.4
Along the north and south walls
parallel to roof OWSJs, out-of-plane
connections between the roof
structure and the perimeter walls are
inadequate.
Along each of the two 54ft long walls,
install
3
additional
out-of-plane
connections between the roof diaphragm
and the concrete perimeter beam. Also,
upgrade existing connections.
Roof
DNA 5143/5144
3
WOOD STREET CENTRE
August 28, 2013
Upper Floor
2.5
Construction details for the Upper
Floor are unknown due to a missing
Upper Floor structural plan.
Investigate to confirm construction
details prior to detailed design.
2.6
The concrete diaphragm capacity is
assumed to have adequate shear
capacity and stiffness based on the
size of the diaphragm.
2.7
At the stairwell (SW) and entry (NE)
locations, there are re-entrant corners
in diaphragm. Details are unknown
and reinforcing is assumed to be
inadequate.
From the underside of the Upper Floor,
install structural steel members to the
underside of the concrete floor
diaphragm in two orthogonal directions
at the re-entrant corner of the roof
diaphragm.
2.8
around the perimeter of the Upper
Floor diaphragm are unknown and
assumed to be inadequate.
diaphragm and to the inside of the
concrete perimeter beam.
2.9
Along the north and south walls
parallel to roof OWSJs, out-of-plane
connections between the Upper Floor
inadequate.
Along each of the two 54ft long walls,
install
3
additional
out-of-plane
connections
between
the
floor
diaphragm and the concrete perimeter
beam.
Also,
upgrade
existing
connections.
2.10
The north wall is a weak/soft storey.
The upper part of the wall is a solid
concrete shearwall, while the lower
part of the wall is a series of nonductile concrete columns. This wall
makes the entire Block very
susceptible
to
torsional
displacements.
Install a new concrete shearwall over a
length of at least three window bays.
Upgrade connection to floor diaphragm
drag strut and to foundation.
2.11
Along the north wall, the non-ductile
concrete columns have inadequate
capacity to support overturning
moments from the solid concrete
shearwall above.
Install reinforced concrete or FRP jackets
around all five concrete columns not part
of the shearwall upgrade.
2.12
In the east wall, the concrete columns
in between doors have inadequate
capacity to support overturning forces
from the solid shearwall above.
Upgrade the compression capacity of
the concrete columns by installing
pilasters/thickenings anchored to existing
wall column sections.
Walls
DNA 5143/5144
4
WOOD STREET CENTRE
August 28, 2013
Foundations
2.13
Along the east wall of Block 1, the
footing is shared with the west
shearwall from Block 2. The footing
steps to a shallower foundation wall
within
the
building
interior.
Foundation capacity is inadequate.
Foundation walls are only partially
reinforced.
Install enlarged footings along the entire
length of the wall. Upgrade foundation
walls by installing a reinforced grade
beam on one side.
2.14
Foundations are inadequate at new
concrete shearwalls along north wall.
At new shearwall location, install
enlarged
footings
and
reinforce
foundation
walls
new
reinforced
concrete.
There is an expansion joint between
the east wall of Block One and the
west wall of Block Two. There does
not appear to be an actual gap
between the two concrete walls, and
adjacent, parallel concrete walls are
not connected together, although
they share a strip footing.
2.15
The roof of Block Two is located at
mid-height of the upper storey of
Block One. Pounding of Block Two’s
roof can compromise the stability of
Block One’s western wall and
columns, which support Block One`s
roof.
The upper floors of each Block are
typically at the same level, except at
the stairwell of Block One.
Creating a structural separation here will
require an extensive amount of work and
be very costly, so the proposed retrofit
concept is based on connecting the two
Blocks together.
In Block One, install a series of diagonal
struts connected to Block One’s west
wall at the level of Block Two’s roof. The
opposite end of the diagonal strut will
connect to a horizontal strut that spans
the width of the Block and is connected
to the roof diaphragm. On the opposite
side of Block One’s west wall, install
horizontal struts in the roof of Block Two
in line with the new diagonal struts in
Block One.
Connect the upper floors, which are at
the same level, together for out-of-plane
loading.
Connect Block One’s west wall to Block
Two’s roof, and connect the upper floors
of each Block together for in-plane
loading.
2.16
Hollow tile partition walls installed
between
the
bathrooms
are
unreinforced
and
inadequately
anchored.
Install new continuous steel angles at the
top of the walls, connecting the wall to
the floor structure above.
2.17
Anchorage and restraint of the brick
chimney could not be confirmed on
drawings or on site.
Remove brick chimney and replace with
new wood frame walls and metal flue.
DNA 5143/5144
5
WOOD STREET CENTRE
2.18
2.19
3.0
The lighting equipment in the Gym is
a potential falling hazard.
Hazardous building materials exist in
the Block.
August 28, 2013
Carry out a review of this non-structural
component for seismic response.
Remove/abate hazardous materials prior
to construction.
BLOCK TWO – CLASSROOM
The roof structure consists of 2” T&G decking on 16” deep open web steel joists spaced at
4’-0” on centre. Above the corridor, the roof structure consists of 1” shiplap on 2x4 joists
spaced at 24” on centre on top of a 4” thick concrete suspended slab. There is also a 4”
thick suspended concrete slab over the stairwells at the northeast and northwest corners.
The Upper Floor structure consists of a 4" concrete slab on 16” deep open web steel joists
spaced at 2’-2” on centre. Above the corridor, the Upper Floor structure is a 5 1/2"
suspended concrete slab supported by reinforced concrete beams and columns on spread
footings.
At the Main Floor level, there is a 4” slab-on-grade. The foundations around the perimeter
of the block include 12” thick, concrete foundation walls on 12” deep x 24” wide concrete
strip footings. Foundation walls are typically unreinforced; although they have continuous
reinforced along the top, and column reinforcing extends to the bottom of the foundation
wall.
The floor and roof structures are supported by reinforced concrete walls, beams and
columns around the perimeter.
Item
Seismic Deficiency
Retrofit Concept
Roof
Install new steel cross bracing on the
underside of the roof.
3.1
The 2” wood decking diaphragm has
inadequate strength and stiffness.
3.2
between the roof diaphragm and
perimeter walls are inadequate on all
four sides and around the stairwells.
underside of the plank decking and to
the inside of the concrete perimeter
beam/wall. Remove and replace the
ceiling adjacent to the wall to facilitate
access.
3.3
The existing perimeter concrete
beams in the north and south walls
provide insufficient capacity as
diaphragm chords.
Introduce a new interior shearwall in the
N-S direction to reduce the diaphragm
span.
DNA 5143/5144
Introduce a new interior shearwall in the
N-S direction to reduce the diaphragm
span.
6
WOOD STREET CENTRE
August 28, 2013
Item
Seismic Deficiency
Retrofit Concept
3.4
Along the north and south walls, the
existing perimeter concrete beam is
discontinuous at the start of the
shearwalls at each end of the wall.
beams provide insufficient capacity as
drag struts between existing concrete
shearwalls along the north and south
walls.
Reduce the demand on drag struts by
introducing new, efficiently spaced
shearwalls in the north and south walls.
3.5
There is no drag strut to tie the roof
diaphragm into the shearwalls on the
interior side of the two stairwells.
On the underside of the roof, install a
continuous structural steel member on
the underside of the roof diaphragm and
beside the concrete shearwall. Connect
to the roof diaphragm and the shearwall.
3.6
At the two stairwell locations, there
are re-entrant corners in the wood
diaphragm
without
adequate
reinforcing.
From the underside of the roof, install
structural steel members to the
underside of the wood decking in two
orthogonal directions at the re-entrant
corners of the roof diaphragm.
3.7
Along the east and west walls parallel
to
roof
OWSJs,
out-of-plane
inadequate where the walls are
connected to the wood diaphragm.
Along each of the two walls, install 3
additional
out-of-plane
connections
between the roof diaphragm and the
concrete perimeter beam. Also, upgrade
existing connections.
3.8
There is no drag strut to tie the roof
diaphragm into the new interior
shearwall.
Install a continuous structural steel
member connected to the underside of
the roof diaphragm and to the new
shearwall.
Upper Floor
3.9
Construction details for the Upper
Floor are unknown due to a missing
Upper Floor structural plan.
3.10
The concrete diaphragm is assumed
to have adequate shear capacity and
stiffness.
3.11
around the perimeter of the Upper
Floor diaphragm are unknown and
assumed to be inadequate.
DNA 5143/5144
Installation of a new interior shearwall
reduces the span of the floor diaphragm.
diaphragm and to the inside of the
concrete perimeter beam.
7
WOOD STREET CENTRE
August 28, 2013
Item
Seismic Deficiency
Retrofit Concept
3.12
Along the north and south walls,
existing concrete perimeter beams
have inadequate capacity for use as
diaphragm chords.
New,
efficiently
spaced
concrete
shearwalls in the north and south walls
and the new north-south interior
shearwall will reduce the diaphragm span
and demand on the chords.
3.13
walls.
New,
efficiently
spaced
concrete
shearwalls in the north and south walls
will reduce the demand on the drag
struts.
3.14
Along the north and south walls, the
existing perimeter concrete beam is
discontinuous at the start of the
shearwalls at each end of the wall.
walls.
Reduce the demand on drag struts by
introducing new, efficiently spaced
shearwalls in the north and south walls.
3.15
There is no drag strut to tie the upper
floor diaphragm into the shearwalls on
the interior side of the two stairwells.
At these two locations, install continuous
steel members on the underside of the
floor connected to the concrete floor
diaphragm and the concrete shearwalls.
3.16
At the stairwell (SW) and entry (NE)
locations, there are re-entrant corners
in diaphragm. Details are unknown
and reinforcing is assumed to be
inadequate.
From the underside of the Upper Floor,
install structural steel members to the
diaphragm in two orthogonal directions
at the re-entrant corner of the roof
diaphragm.
3.17
There is no drag strut to tie the upper
floor diaphragm into the new interior
shearwall.
Install a continuous structural steel
member connected to the underside of
the diaphragm and to the new shearwall.
3.18
Along the east and west walls parallel
to
floor
OWSJs,
out-of-plane
connections between the floor
inadequate.
Along each of the two walls, install 3
additional
out-of-plane
connections
concrete perimeter beam. Also, upgrade
existing connections.
DNA 5143/5144
8
WOOD STREET CENTRE
Item
August 28, 2013
Seismic Deficiency
Retrofit Concept
3.19
There is inadequate strength and
ductility in the north and south
perimeter walls.
Install two 16 ft long concrete shearwalls
in each of the north and south walls.
Upgrade drag strut connections to the
new shearwalls at the roof and upper
floor levels.
3.20
Reduce the demand on the existing
diaphragms, chords and struts and
on the existing shearwalls and
foundations by introducing a new
interior full-height shearwall.
Install a new 25 ft long concrete
shearwall on the south side of the
corridor between the two classrooms on
the southeast end of the Block. The new
concrete shearwall will be continuous
from the foundation to the roof.
3.21
In the west wall, the concrete
columns in between doors have
inadequate capacity to support
primary gravity loads from the corridor
beam plus overturning forces from the
solid shearwall above.
Upgrade the compression capacity of
the concrete columns by installing
pilasters/thickenings anchored to existing
wall column sections.
Walls
Foundations
3.22
Existing unreinforced foundations are
inadequate at locations of new
concrete shearwalls along north and
south walls
At new shearwall locations, install
enlarged footings/grade beams and
reinforce foundation walls with a
concrete overlay.
3.23
Along the west wall of Block 2, the
footing is shared with the east
shearwall from Block 1. The footing
steps to a shallower foundation wall
within
the
building
interior.
Foundation capacity is inadequate.
Foundation walls are only partially
reinforced.
Install enlarged footings along the entire
length of the wall. Upgrade foundation
walls by installing a concrete overlay.
3.24
The
existing
slab-on-grade
is
inadequate to support the new interior
concrete shearwall.
Install new concrete foundations under
the new interior shearwall.
3.25
See
Block
One
adjacency/pounding comments.
3.26
Hollow tile partition walls installed in
the stairwell are a falling hazard.
DNA 5143/5144
for
Remove hollow tile walls in the stairwell
and replace with reinforced concrete
block.
9
WOOD STREET CENTRE
Item
3.27
4.0
Seismic Deficiency
this Block.
August 28, 2013
Retrofit Concept
to construction.
FINDINGS









In the north wall of Block One, there is a vertical discontinuity of the concrete
shearwall to the foundation, classifying this block as a weak/soft storey highly
susceptible to excessive displacements due to torsionional effects.
The two adjacent Blocks are two stand-alone building structures with no actual
separation gap between them. The roof of Block One is higher than that of Block
Two. Pounding of the lower roof into the wall and columns of the Block One can
compromise the integrity of the primary gravity support system for the Block One
roof.
Load paths and diaphragm collector elements are typically inadequate throughout
both Blocks.
T&G wood roof diaphragms have inadequate strength and stiffness to support
perimeter concrete walls.
Anchorage of perimeter walls to diaphragms is typically inadequate for walls that
are parallel to joist spans.
Wall construction is typically concrete shearwall or moment frame.
o Concrete shearwalls typically satisfy minimum reinforcing requirements for
walls to avoid being classified as non-ductile; however, the walls typically
lack adequate boundary reinforcing elements and are considered to be
slender in some cases. There is inadequate boundary tension anchorage
to the unreinforced foundations.
o Concrete moment frames are non-ductile and are governed by the
capacity of the columns, which are also the primary load-carrying support
members. Concrete moment frames typically have inadequate capacity
and stiffness, where drag struts are inadequate to carry load into existing
shearwalls.
Foundations are mostly unreinforced.
Non-structural falling hazards include an unreinforced masonry chimney and hollow
tile block partition walls, which are located at means of egress locations
Hazardous building materials that exist in this Block should be removed/abated
DNA 5143/5144
10
WOOD STREET CENTRE
5.0
August 28, 2013
below:
Wood Street Centre Seismic Upgrading
Item
Block 1
Block 2
Total
Construction Year
1954
1954
-
Description
Original
Addition
-
Total Area
7,776 sf
12,960 sf
20,736 sf
$97,180
$173,500
$270,680
$61,400
$99,500
$160,900
$59,700
$258,535
$318,235
Foundations
$108,000
$154,500
$262,500
Miscellaneous and Non-Structural7
$96,300
$20,000
$116,300
Subtotal 1
$422,580
$706,035
$1,128,615
$76,064
$127,086
$203,150
$77,760
$129,600
$207,360
Subtotal 2
$576,404
$962,721
$1,539,126
$115,281
$192,544
$307,825
$115,281
$192,544
$307,825
Consultant Fees (15%)6
$103,753
$173,290
$277,043
Total
$910,719
$117 / sf
$1,521,100
$117 / sf
$2,431,818
$117 / sf
Roof7
7
Upper Floor
Walls7
7
Note:
1. This cost estimate shall be read in conjunction with DNA’s report on the Seismic
Evaluation of Various Yukon Schools (August 28, 2013).
4. The cost estimate is an ASTM Class 4 Cost Estimate with an expected accuracy between
+30% and -20% for a project that is defined up to 15% complete. No drawings are
developed as part of this cost estimate.
5. The cost estimate does not include soft costs, such as taxes, moving costs, temporary
facilities, loss of use/revenue, etc.
6. Consultant fees are calculated as a percentage of the subtotal of all elements except the
construction contingency.
DNA 5143/5144
11
WOOD STREET CENTRE
APPENDIX A
Block Plan
DNA 5143/5144
August 28, 2013
NORTH
WOOD STREET CENTRE
APPENDIX B
Photographs
DNA 5143/5144
August 28, 2013
SEIS
SMIC EVALU
UATION OF VARIOUS YU
UKON SCHO
OOLS
WOOD STREET
T CENTRE
South and East Elevation
ns
Typical caanopy at exit
A 5143/5144
4
DNA
August 28
8, 2013
SEIS
SMIC EVALU
UKON SCHO
OOLS
WOOD STREET
T CENTRE
Soft/We
eak storey on north side of Block One
A 5143/5144
4
DNA
August 28
8, 2013
SEIS
SMIC EVALU
UKON SCHO
OOLS
WOOD STREET
T CENTRE
Main
M
Floor corrridor in Block Two
Underside
e corridor slab
b in Main Floorr in Block Two
o
A 5143/5144
4
DNA
August 28
8, 2013
SEIS
SMIC EVALU
UKON SCHO
OOLS
WOOD STREET
T CENTRE
Upp
per Floor Classsroom in Blocck Two
Gymnasium
m in Block On
ne
A 5143/5144
4
DNA
August 28
8, 2013
SEIS
SMIC EVALU
UKON SCHO
OOLS
WOOD STREET
T CENTRE
Concrete
e stair at north
hwest corner o
of Block Two
A 5143/5144
4
DNA
August 28
8, 2013
WOOD STREET CENTRE
August 28, 2013
APPENDIX C
Building System
DNA 5143/5144
CH
HRIST
T THE KING ELEMENTARY
SE
EISMIC EV
VALUATION
OF
F VARIOU
US YUKO
ON SCHOOLS
Aug
gust 28, 2013
Yukon schools.
DNA
A 5143/5144
4
August 28, 2013
TABLE OF CONTENTS
1.0
2.0
3.0
4.0
5.0
6.0
7.0
BLOCK TWO – 1965 ADDITION
BLOCK FOUR – 2001 ADDITION
FINDINGS
3
3
5
7
10
12
13
APPENDICES
Appendix A
Appendix B
Appendix C
DNA 5143/5144
Block Plan
Photographs
System
2
1.0
August 28, 2013
Christ the King was originally constructed in 1960 with a one-storey classroom section
connected to the south of a gymnasium. In 1965, there was a small corridor/classroom
extension to the southeast and a six classroom extension to the southwest of the 1960
classrooms. In 1982, there was an addition to the southwest of the 1965 extension and a
change room addition to the east of the gymnasium. In 2001, there was another classroom
addition at the east corner of the school.
2.0
The roof structure in the gym is 4x8 T&G decking spanning 15’-0” on 9”x34 1/2" glulam
beams and 10”x10” timber columns. Above the stage and adjacent rooms, the roof
structure is 1” horizontal shiplap on 2x12 roof joists. Exterior walls in the gym are framed
with 2x8 studs and sheathed with diagonal shiplap.
The roof structure in the one-storey classroom block surrounding the gym is framed with
shiplap sheathing on dimensional lumber joists supported by 2x6 stud walls and diagonally
sheathed shiplap on the exterior.
Perimeter and interior foundations are typically reinforced concrete foundation walls and
strip footings at 5 ft below grade. Foundation walls are typically 8” thick, except for Gym
end walls, which are 10” thick. The main floor is a 4” thick concrete slab-on-grade.
In the 1965 classroom addition to the southwest end of the 1960 classroom area, the
construction is similar, so the 1965 classroom addition is included as part of this block.
Item
Seismic Deficiency
Retrofit Concept
The roof diaphragm in the gym does
not
have
adequate
capacity,
diaphragm chords and load paths
into perimeter walls.
Install plywood sheathing nailed to the
underside of the existing wood decking
and connected to the glulam roof
beams. Above the stage and adjacent
rooms, additional blocking will be
required for plywood nail attachment on
the underside of the 1” shiplap. Install a
new ceiling on the underside of the
plywood.
Roof
2.1
Install continuous steel angles around the
perimeter of the gym connected to the
underside of the wood decking and to
the inside of the wall.
DNA 5143/5144
3
Item
Seismic Deficiency
In the 1960 and 1965 classroom
areas:
does not have adequate shear
capacity.
2.2
The existing roof diaphragm does not
have
adequate
diaphragm
chords/drag
struts
along
the
northwest and southeast walls.
have adequate load paths into new
perimeter shearwalls on the northwest
and southeast sides of the block.
have adequate load paths into
existing/new shearwalls in the
northwest-southeast direction.
August 28, 2013
Retrofit Concept
Remove roofing and install new plywood
sheathing on top of the existing shiplap.
At the time of roof diaphragm upgrade,
install blocking between roof joists at
perimeter walls in the northeastsouthwest direction. Install continuous
light gauge metal strap ties on top of the
plywood into the blocking.
Above shearwall locations, connect the
new blocking to the tops of the new
shearwalls.
Add connections between the roof
diaphragm and the shearwalls in the
northwest-southeast direction.
Main Floor
2.3
Walls
2.4
The walls on the southwest side of
the gym do not have adequate shear
capacity due to lack of diagonal
board sheathing or structural plywood
on the majority of the wall.
Install plywood sheathing on the inside of
the wall. Upgrade load paths in to the
foundation.
2.5
The wall on the south side of the
corridor at the northeast end of the
classroom block does not have
adequate shear capacity.
Install plywood sheathing on both sides
of the wall.
Upgrade load path
connections top and bottom.
2.6
The walls in the northeast-southwest
direction of the classroom block do
not have adequate shear capacity.
Install at least three solid plywood
shearwalls on the exterior on each side
of the building. The shearwalls shall be
approximately evenly spaced. Upgrade
load path connections top and bottom.
Foundations
2.7
DNA 5143/5144
4
Item
Seismic Deficiency
August 28, 2013
Retrofit Concept
2.8
2.9
3.0
The front entrance canopy is not
adequately anchored to the building
structure for out-of-plane loading.
Hazardous building materials may
exist in certain building components.
Upgrade connections.
to construction.
The roof structure of the 1965 addition to the southeast of the 1960 building consists of
shiplap sheathing on dimensional lumber joists supported by wood stud walls and glulam
beams on the interior and wood stud walls and double 2x8 headers around the perimeter.
Along the south wall, roof joists are supported by a ledger connection to an unreinforced
concrete block wall that is shared with the future 1982 addition.
Perimeter and interior foundations are typically 8” thick reinforced concrete foundation walls
and strip footings founded at 5 ft below grade. The main floor is a 4” thick concrete slabon-grade.
Item
Seismic Deficiency
Retrofit Concept
The roof diaphragm has inadequate
strength and stiffness.
Install plywood sheathing on top of
existing horizontal shiplap.
3.2
The roof diaphragm of this block is
not adequately connected to Block 1.
Install a continuous drag strut at the roof
level continuous from the southeast end
of Block 2 to the front entrance canopy
in Block 1. Connect the drag strut to
shearwalls.
3.3
There’s an expansion joint in the roof
where the 1965 addition connects to
the 1960 building. The expansion
joint isn’t functional anymore due to
the nature of the surrounding
construction.
Connect the roof together on each side
of the expansion joint. Upgrade load
paths between the roof diaphragm and
the diagonally sheathed wall below.
3.4
The out-of-plane connection between
the roof diaphragm and the concrete
block wall is not detailed to avoid
cross-grain
bending
and
is
inadequate.
Upgrade out-of-plane anchorage by
installing strap ties anchored to the roof
joists and the concrete block bond beam
at 4’-0” on centre.
Roof
3.1
DNA 5143/5144
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Item
Seismic Deficiency
August 28, 2013
Retrofit Concept
Walls
3.5
3.6
The concrete block wall on the south
side of the Block is mostly
unreinforced; constructed in stack
pattern; has inadequate shear
capacity, anchorage and ductility; and
has a negative impact on the
assessment and performance of the
rest of the building. This load-bearing
wall is not adequate for in-plane and
out-of-plane loading.
There is inadequate shear capacity in
the walls on the northeast side of the
block.
Install vertical reinforcing in the wall to
enhance in-plane and out-of-plane
capacity by cutting vertical slots in the
face shells of the masonry walls and
adding vertical reinforcing doweled into
the existing foundation at the bottom of
the wall and bond beam at the top of the
wall.
Install horizontal FRP strips along the
masonry wall to enhance the in-plane
shear capacity.
Upgrade a 25 ft long and 30 ft long
section of wall shared with Block 4 by
installing plywood on one side and
upgrading load paths top and bottom.
Main Floor
3.7
Foundations
3.8
3.9
Hazard materials may exist in certain
DNA 5143/5144
to construction.
6
4.0
August 28, 2013
The roof of Block 3 is framed with 1 1/2" thick T&G fir decking in controlled random pattern
on open web steel joists and channels spaced at 6 ft on centre. Roof joists are supported
around the perimeter and on the interior by partially reinforced concrete block walls laid in
stack pattern, which are 10” thick around the Industrial Arts wing at the south corner and 8”
thick elsewhere. Concrete block walls sit on reinforced concrete foundation walls and
footings founded 5 ft below grade on the interior and perimeter.
There’s a small mezzanine in the Industrial Arts wing that is framed with 5/8” thick plywood
on wood joists and steel beams supported by concrete block walls and steel columns.
In 1982, there was a double change room addition constructed on the southeast side of the
gym. The roof consists of 1 1/2" T&G wood decking on open web steel joists supported by
partially reinforced and grouted, non-ductile concrete block walls laid in stack pattern. The
foundation consists of reinforced concrete foundation walls and strip footings on three
sides. The main floor is an 8” thick suspended concrete slab supported by grade beams
and pedestals on spread footings. There is no structural connection between this addition
and the Block 1 gym.
Item
Seismic Deficiency
Retrofit Concept
4.1
The roof diaphragm has inadequate
capacity and stiffness.
existing wood decking. Install diaphragm
chords/struts at perimeter walls as
required.
4.2
Roof
diaphragm
out-of-plane
anchorage to the concrete block wall
shared with Block 2 is not detailed to
limit cross grain bending in the wood
ledger.
installing steel angles connected to the
underside of the roof decking and bolted
to the concrete block bond beam.
4.3
Roof
diaphragm
out-of-plane
anchorage to the concrete block walls
parallel to roof joists is not adequate
for seismic loading.
installing steel angles connected to the
to the concrete block bond beam.
4.4
diaphragm and concrete block walls
perpendicular to roof joists are
inadequate in the perimeter walls and
each side of the corridor.
Install steel angles connected to the
to the inside of the existing concrete
block bond beam.
Roof
Roof – 1982 Change Rooms
4.5
The roof diaphragm is not adequately
connected to the wall behind the
Block 1 stage. The 1982 roof could
pound into the stage wall.
DNA 5143/5144
Above the roof, upgrade the connection
of the roof to the Block 1 wall.
7
Item
Seismic Deficiency
August 28, 2013
Retrofit Concept
Walls
4.6
All structural walls are load-bearing
concrete block walls constructed in
stack pattern. There is typically only
one bond beam at the tops of the
walls, while there is joint reinforcing
every three courses.
Vertical
reinforcing is typically spaced at 12 ft
on centre. These walls do not have
minimum reinforcing for seismic
requirements for stack pattern
masonry. Due to their load bearing
nature, poor ductility, and poor
performance in seismic conditions for
in-plane and out-of-plane loading, all
of these walls need to be retrofitted.
Install vertical reinforcing in the wall to
increase in-plane and out-of-plane
capacity by cutting vertical slots in the
face shells of the masonry walls and
adding vertical reinforcing doweled into
the existing foundation at the bottom of
the wall and bond beam at the top of the
wall.
Install horizontal FRP strips along the
masonry wall to enhance the in-plane
shear capacity.
4.7
In the upper floor of the mechanical
room, there is a concrete block guard
rail that does not appear to have
vertical reinforcing or anchorage to
perpendicular walls at each end,
making it a falling hazard.
Connect the existing bond beam at the
top of the guard wall to the concrete
block walls at each end.
4.8
At the doorway in the wall shared
between Block Three and Block Two,
there is unreinforced concrete block
above the doorway lintel that is
unsupported at the top and a falling
hazard.
Connect the unreinforced block by
drilling holes through the lintel; epoxy
dowelling rebar into the lintel; and solid
grouting the unreinforced block above at
dowel locations. Install a bond beam at
the top. Upgrade connections of the
lintel to the structural wall, as required.
4.9
At the north corner of Block 3, a 14 ft
long section of concrete block wall
was added to the outside of the
corridor exterior wall of Block 2; but
this wall is not anchored to the Block
2 roof and is freestanding.
Provide anchorage connection of this
freestanding wall to the Block 2 roof.
4.10
Some interior concrete block walls
only extend to the height of the
dropped ceiling and are not anchored
to the roof diaphragm.
Install a steel brace system connecting
the top of the concrete block walls to the
roof diaphragm.
4.11
Some interior concrete block walls in
the change rooms near the gym only
extend to the height of the dropped
ceiling are not anchored to the roof
diaphragm.
Install a series of diagonal braces spaced
out along the top of the walls. Connect
the braces to a continuous member
anchored to the top of the wall and
another continuous member connected
to the roof diaphragm.
DNA 5143/5144
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August 28, 2013
Main Floor
4.12
Foundations
4.13
4.14
Hazard materials may exist in certain
DNA 5143/5144
to construction.
9
5.0
August 28, 2013
BLOCK FOUR – 2001 ADDITION
The Block Four roof level is constructed at an elevation higher than the Block Two roof, and
there is a narrow clerestory along the corridor in the middle of the block. The roof is
typically framed with 1/2” thick plywood on wood trusses and joists supported by wood
and steel stud walls sheathed with plywood on the exterior and drywall on the interior.
Around the exterior, stud walls are supported by reinforced concrete foundation walls and
strip footings. On the interior, walls are supported by reinforced concrete strip footings or
slab thickenings.
The architectural details booklet was not available for our review, so several construction
details referenced on the architectural drawings are unknown. Retrofit concepts for this
block should be reviewed should this detail booklet become available.
Item
Seismic Deficiency
Retrofit Concept
5.1
There’s a large hole in the middle of
the roof diaphragm due to the
clerestory in the middle of the block.
The lower roof diaphragm does not
appear to be detailed to handle
potential
stress
concentrations
around the opening.
Install drag struts at the lower roof level
on each side of the opening. Extend the
drag struts along the corridor in one
direction and into the lower roof in the
other direction.
5.2
Due to the large clerestory opening in
the lower roof diaphragm, the existing
roof diaphragm does not have
adequate capacity to transfer loads to
shearwalls.
Upgrade corridor walls in the long
direction of the clerestory by installing
plywood on one side and upgrading load
paths top and bottom.
5.3
Drag strut continuity is unknown on
the southwest side of the block.
Install a continuous drag strut at the roof
level along the southwest side of Block 4
all the way to the gym wall. Connect the
drag strut to the shearwalls below.
5.4
At the northwest side of the block,
there does not appear to be adequate
in-plane connections between the
Block 4 roof and the Block 3 change
room roof/wall.
Upgrade the existing corridor wall into a
plywood shearwall from the inside and
upgrade load paths top and bottom.
Roof
DNA 5143/5144
10
Item
August 28, 2013
Seismic Deficiency
Retrofit Concept
the walls, complicated by the inability
of the donut-shaped roof diaphragm
to transfer loads to the walls.
Upgrade existing 40 ft long and 12 ft
long walls in the northeast-southwest
direction along the corridor at the
southeast corner of the block by
installing new wood studs within the steel
stud wall assembly, and install plywood
on the corridor one side of the wall.
Upgrade load paths top and bottom.
Walls
5.5
Walls on the southwest side of the block
have upgrade details described in the
Block 2 section.
5.6
The clerestory roof diaphragm does
not have adequate stiffness and
strength due to its high aspect ratio.
Also, the narrow end walls have large
windows and have inadequate shear
capacity. Perimeter clerestory walls
are platform framed.
Install two interior steel cross braces
between the lower roof level and the top
of the clerestory walls. Add connections
to the roof diaphragm and drag struts
into the lower roof.
Main Floor
5.7
Foundations
5.8
5.9
There are no post cap connections at
the top of the columns in the canopy
on the northeast side of the Block.
Install new post cap connections.
5.10
The roof framing above the ramp into
the portable building is laterally
unstable under lateral loading.
Upgrade the connection of the roof
structure into the portable walls.
Upgrade post-to-beam connections.
DNA 5143/5144
11
6.0
August 28, 2013
FINDINGS








The seismic assessment and performance of Christ the King Elementary is
complicated by several factors:
o The school consists of several additions constructed at various points in
time.
o The plan shape of the building is irregular.
o There are several different roof levels.
o Several of the structural wall components are considered to be non-ductile
with respect to seismic performance, and their locations in the school
impact the performance of the entire school.
There is a significant amount of load-bearing concrete block walls that are
constructed in stack pattern with minimal reinforcing. These walls have limited
capacity, poor ductility and poor performance in past earthquakes. The entire
1982 additions were constructed using this method, and due to the way the blocks
are tied together, the entire school is impacted.
Several roof diaphragms are constructed with horizontal shiplap or wood decking,
which are limited in terms of strength and stiffness.
Most of the wall systems throughout the building are typically non-ductile and
limited in capacity.
There is generally a lack of drag strut continuity to tie the different sections of the
school together.
There are several non-structural concrete block walls that are not adequately
supported at the top of the wall and are falling hazards.
Existing foundations are typically sufficient.
prior to construction. Retrofit of concrete block walls is complicated by the
presence of vermiculite-containing loose-fill insulation in the voids.
DNA 5143/5144
12
7.0
August 28, 2013
below:
Christ the King Elementary Seismic Upgrading
Item
Block 1
Block 2
Block 3
Block 4
Total
Construction Year
1960
1965
1982
2001
-
Description
Original
Addition
Addition
Addition
-
Total Area
14,765 sf
3900 sf
9005 sf
6395 sf
34,065 sf
$418,820
$35,686
$197,495
$186,427
$838,428
$0
$0
$0
$0
$0
$98,598
$87,015
$552,932
$47,724
$786,269
Foundations
$0
$0
$0
$0
$0
Miscellaneous and
Non-Structural7
$2,500
$0
$0
$3,800
$6,300
Subtotal 1
$519,918
$122,701
$750,427
$237,951
$1,630,997
Additional Arch
(10%), Mech (5%),
Elec (3%)
$93,585
$22,086
$135,077
$42,831
$321,299
Hazardous
Materials ($10/sf)
$147,650
$39,000
$90,050
$63,950
$340,650
Subtotal 2
$761,153
$183,787
$975,554
$344,732
$2,265,226
Contractor
Overhead and
Profit (20%)
$152,231
$36,757
$195,111
$68,946
$453,045
Construction
Contingency (20%)
$152,231
$36,757
$195,111
$68,946
$453,045
Consultant Fees
(15%)6
$137,008
$33,082
$175,600
$62,052
$407,741
Total
$1,202,622
$81 / sf
$290,384
$74 / sf
$1,541,375
$172 / sf
$544,677
$85 / sf
$3,579,058
$105 / sf
7
Roof
Main Floor7
7
Walls
7
Note:
1. This cost estimate shall be read in conjunction with DNA’s report on the Seismic Evaluation of
Various Yukon Schools (August 28, 2013).
4. The cost estimate is an ASTM Class 4 Cost Estimate with an expected accuracy between +30%
and -20% for a project that is defined up to 15% complete. No drawings are developed as part of
this cost estimate.
5. The cost estimate does not include soft costs, such as taxes, moving costs, temporary facilities,
loss of use/revenue, etc.
DNA 5143/5144
13
APPENDIX A
Block Plan
DNA 5143/5144
August 28, 2013
NORTH
APPENDIX B
Photographs
DNA 5143/5144
August 28, 2013
SEIS
SMIC EVALU
UKON SCHO
OOLS
CHR
RIST THE KIING ELEMEN
NTARY
Block One gym
Bloc
ck one classro
oom (1960 and 1965)
A 5143/5144
4
DNA
August 28
8, 2013
SEIS
SMIC EVALU
UKON SCHO
OOLS
CHR
NTARY
Southweest elevation
Blocck Three
A 5143/5144
4
DNA
August 28
8, 2013
SEIS
SMIC EVALU
UKON SCHO
OOLS
CHR
NTARY
Block
B
Three so
outheast elevaation
Block 4 sou theast elevatio
on
A 5143/5144
4
DNA
August 28
8, 2013
SEIS
SMIC EVALU
UKON SCHO
OOLS
CHR
NTARY
Block 4 norrthwest canop
py
1982 cclassroom
A 5143/5144
4
DNA
August 28
8, 2013
SEIS
SMIC EVALU
UKON SCHO
OOLS
CHR
NTARY
Block On e gym interiorr
Block Threee change room
m
A 5143/5144
4
DNA
August 28
8, 2013
SEIS
SMIC EVALU
UKON SCHO
OOLS
CHR
NTARY
Block
B
Four cleerestorey corrridor
Block Fou
ur roof framing
g
A 5143/5144
4
DNA
August 28
8, 2013
SEIS
SMIC EVALU
UKON SCHO
OOLS
CHR
NTARY
Bloc
ck Three soutthwest entry/ccorridor
Block Three roof/wall fram
ming
A 5143/5144
4
DNA
August 28
8, 2013
SEIS
SMIC EVALU
UKON SCHO
OOLS
CHR
NTARY
Block Threee mezzaninee
Po
ortable
A 5143/5144
4
DNA
August 28
8, 2013
August 28, 2013
APPENDIX C
Building System
DNA 5143/5144
SE
ELKIRK ELE
EMENT
TARY
SE
EISMIC EV
VALUATION
OF
F VARIOU
US YUKO
ON SCHOOLS
Aug
gust 28, 2013
Yukon schools.
DNA
A 5143/5144
4
SELKIRK ELEMENTARY
August 28, 2013
TABLE OF CONTENTS
1.0
2.0
3.0
4.0
5.0
6.0
FINDINGS
3
3
6
8
10
11
APPENDICES
Appendix A
Appendix B
Appendix C
DNA 5143/5144
Block Plan
Photographs
System
2
SELKIRK ELEMENTARY
1.0
August 28, 2013
Selkirk was originally constructed in 1958 with a two-storey classroom section adjacent to a
one-storey area with miscellaneous rooms. In 1972, there was a one-storey classroom
addition to the northwest, and in 1977, there was a one-storey gymnasium addition to the
west of the 1972 addition. For evaluation purposes, the school is spilt into three blocks.
2.0
The pitched roof structure above the two-storey classroom wing at the south end of the
Block and the one-storey area at the north end of the block consists of 1” thick diagonal
shiplap on 2x4 purlins spaced at 16” on centre supported by wood trusses. In the
classroom wing, roof trusses are supported by reinforced studs, and in the one-storey area,
roof trusses are supported by 8 1/2” wide wood columns at 4’-0” on centre. The onestorey flat roof between the two pitched roof areas consists of 1” thick horizontal shiplap on
dimensional lumber joists and wood stud walls.
The upper floor structure in the two-storey classroom wing consists of a 3/8” plywood
subfloor on 1” thick shiplap and 3x14 wood joists spaced at 16” on centre above the 24’-0”
wide classrooms and 2x8 wood joists spaced at 16” on centre above the 9’-6” wide
corridor. Upper floor joists are supported by triple 2x6 continuous wood headers and
columns around the perimeter and by 2x6 stud walls along the corridor. Perimeter stud
walls are sheathed with 1” diagonal shiplap.
The main floor structure is a 4” thick concrete slab-on-grade reinforced with wire mesh.
There are underslab mechanical duct trenches on the inside of the perimeter foundations
and in some locations within the building footprint.
Perimeter foundations are typically 8” thick reinforced concrete foundation walls on 1’-8”
wide reinforced concrete footings. Interior partitions are supported by reinforced concrete
slab thickenings.
Item
Seismic Deficiency
Retrofit Concept
In the long direction of the building,
there is a high demand on the roof
diaphragm due to the lack of ductility
in the walls in the long direction of the
building.
The roof diaphragm
capacity is inadequate.
Upgrade perimeter shearwalls in the long
direction of the building to plywood
shearwalls.
Above the two-storey classroom, the
in-plane load paths between the
diaphragm and the perimeter walls is
not adequate.
At perimeter walls, remove the overhang
soffit adjacent to the exterior wall and
wall finishes at the top of the wall. Install
blocking between alternate overhang
outriggers and connect the blocking to
the roof diaphragm and to the walls
below.
Roof
2.1
2.2
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SELKIRK ELEMENTARY
August 28, 2013
Item
Seismic Deficiency
Retrofit Concept
2.3
Above the two-storey classroom,
there is inadequate diaphragm
chord/strut continuity along the walls
in the long direction.
Remove wall finishes at the top of the
two long walls to expose double blocking
between trusses. Install a continuous
light gauge metal strap along the top of
the wall.
2.4
In the middle, one-storey section of
the Block, there are inadequate load
paths between the roof diaphragm
and new shearwalls.
At new shearwall locations, install new
blocking between roof joists, and
connect the blocking to the roof
diaphragm and the wall.
The connection between the middle
one-storey lower roof to the adjacent
sections of the Block is unknown.
Upgrade the connection of the lower roof
to the adjacent sections of the Block by
locally removing a strip of roofing along
adjacent walls and install a continuous
steel angle connecting the roof and wall.
Repair roofing after.
Along the northeast wall, there is
inadequate drag strut continuity to
drag load into the end shearwall.
Remove wall finishes at the top of the
wall to expose the top of the wall. Install
a continuous light gauge metal strap
along the top of the wall. Upgrade load
path connections at the top of the
shearwall.
2.5
2.6
Upper Floor
2.7
In the long direction of the building,
there is a high demand on the upper
floor diaphragm due to the lack of
ductility in the walls in the long
direction of the building. The upper
floor
diaphragm
capacity
is
inadequate.
Upgrade perimeter shearwalls in the long
direction of the building to plywood
shearwalls.
2.8
In the two-storey classroom, there is
inadequate diaphragm chord/strut
continuity along the walls in the long
direction.
Remove wall finishes at the floor level in
the two long walls to the exterior side of
the floor structure. Install a continuous
light gauge metal strap on the outside of
the wall at the floor level.
2.9
At the upper floor level, there is
inadequate diaphragm continuity
around stairwell openings.
Install drag struts on the underside of the
floor in two directions at stairwell
openings in the floor.
Main Floor
2.10
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SELKIRK ELEMENTARY
Item
August 28, 2013
Seismic Deficiency
Retrofit Concept
2.11
At the north end of the two-storey
classroom, the diagonal shiplap wall
sheathing is assumed to be
discontinuous below the lower roof
level, resulting in inadequate shear
capacity.
Open the wall below the lower roof level,
and install new plywood sheathing.
2.12
In the two-storey classroom, there is
inadequate overturning capacity in the
end walls in the short direction.
Install new holdowns across the upper
floor assembly and to the foundations.
Anchorage of shearwalls
foundation is inadequate.
Along the short walls at each end of the
two-storey classroom, open up the
bottom of the shearwalls and install new
anchors between the wall bottom plates
and the foundation.
Walls
2.13
to
the
In the long direction of the two-storey
classroom, there is inadequate shear
strength, stiffness and ductility in the
walls.
Install a series of plywood shearwalls
from the foundation to the roof in the
perimeter walls in the long direction of
the building. Install the plywood on the
exterior side of the walls, and upgrade
load path connections. Where windows
are closed in, move windows to existing,
adjacent insulated panel locations.
2.15
In the middle, one-storey section,
there is inadequate shear capacity in
the long direction of the Block.
Upgrade the wall on the northwest side
of the mechanical room and on the
corridor side of the mechanical room to
plywood shearwalls. Upgrade load path
connections at the top and bottom of the
walls.
2.16
In the northeast pitched roof section
of the Block, there is inadequate
shear capacity in the wall shared with
the middle, one-storey section.
Upgrade the wall shared with the onestorey section by installing plywood
sheathing and load path connections on
the pitched roof section side of the wall.
2.14
Foundations
2.17
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SELKIRK ELEMENTARY
August 28, 2013
2.18
2.19
3.0
and is not adequately anchored to the
structure.
Asbestos-containing materials may
Remove and replace the brick chimney
with a new wood frame chase and metal
flue.
to construction.
The roof structure consists of 1 1/2” thick 22 gauge steel decking on 30” and 16” deep
open web steel joists (OWSJs) and steel beams supported by steel columns. Reinforced
concrete spread footings under the frost line and pedestals support the steel columns on
the interior and perimeter of the building. Perimeter pedestals are tied together with 3’-6”
deep by 8” wide reinforced concrete grade beams, while interior pedestals are isolated.
Perimeter walls are wood stud walls infilled between steel columns with wall plates bolted
to the underside of the steel roof beams and to the top of the concrete grade beams.
Perimeter walls are sheathed with 1/2” thick plywood. Interior walls are typically steel stud
walls that are discontinuous at the suspended ceiling and not connected to the roof.
Item
Seismic Deficiency
Retrofit Concept
3.1
The roof diaphragm capacity and
ductility is inadequate.
Upgrade the roof diaphragm from above
by installing new powder-actuated
fasteners into the steel roof framing and
by lapping and screwing steel deck side
laps with continuous light gauge bent
plates.
3.2
Roof
diaphragm
inadequate.
Around the perimeter of the Block, install
a continuous steel angle on top of and
connected to the steel decking.
Roof
3.3
chords
are
There is inadequate roof diaphragm
chord continuity at offsets in the
perimeter of the roof.
DNA 5143/5144
At the two perimeter roof offsets, install
new steel angle diaphragm chords with
continuity connections on the underside
of the steel decking. Connect to the
decking,
splice
to
existing
beams/OWSJs, and splice across
existing OWSJs where required.
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SELKIRK ELEMENTARY
August 28, 2013
Item
Seismic Deficiency
Retrofit Concept
3.4
Parallel to OWSJs, along the
northeast and southwest perimeter
walls, in-plane load paths between
the roof diaphragm and wood
Install a continuous steel angle on the
underside of the steel roof decking,
screwing it into the sides of the existing
wood stud double top plate. From
above the roof during the roof diaphragm
upgrade, connect the steel deck to the
angle with powder-actuated fasteners.
3.5
Perpendicular to OWSJs, in-plane
load path connections between the
roof diaphragm and wood shearwalls
is inadequate.
During the roof diaphragm upgrade,
screw the existing steel deck to the
existing wood framing between the
OWSJs. Use continuous steel plates to
lap the steel decking and the wood
framing as required.
Walls
3.6
Main Floor
3.7
Foundations
3.8
3.9
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to construction.
7
SELKIRK ELEMENTARY
4.0
August 28, 2013
This Block consists of a tall Gym, Stage and Music Room surrounded on two sides by a
lower roof covering a corridor, change rooms, bathrooms, storage, and others.
The roof structure throughout the block is 1 1/2" thick 22 gauge steel metal deck on open
web steel joists (OWSJs). Around the Gym, Stage and Music Room, the roof OWSJs are
supported by partially grouted and reinforced concrete block masonry that is 12” thick,
except around the Music Room, where it is 10” thick. The OWSJs around the lower roof
area are supported by the concrete block wall shared with the Gym on one side and by
steel columns on the other side. Perimeter infill walls between steel columns are typically
framed with wood studs sheathed with plywood.
The foundations in this Block are reinforced concrete grade beams supported by
reinforced concrete pedestals and spread footings founded below frost depth.
Item
Seismic Deficiency
Retrofit Concept
Roof
4.1
The welded and button-punched steel
deck does not have adequate
capacity and ductility.
Above the Gymnasium and Stage,
remove roofing and upgrade the steel
roof deck diaphragm by installing
powder-actuated fasteners to the steel
roof framing and by screwing the side
laps together over new light gauge metal
bent plate.
Upgrade the in-plane
anchorage of the roof diaphragm to
perimeter walls.
In the lower roof area, introduce drag
struts and some interior shearwalls in the
northeast-southwest direction.
4.2
There is inadequate out-of-plane
anchorage between the roof and the
concrete block walls parallel to
OWSJs.
Along all of the concrete block walls
parallel to roof OWSJs, install new steel
angles on the underside of the steel roof
deck over two joist bays. Install at 8’-0”
on centre and connect to the roof
diaphragm and the concrete block wall.
4.3
The in-plane anchorage of the lower
roof
diaphragm
to
the
Gym/Auditorium concrete block wall
is inadequate.
steel angles connected to the underside
of the steel roof deck and to the side of
the concrete block wall.
The in-plane anchorage of the lower
roof diaphragms to the perimeter
walls is inadequate.
steel angles connected to the underside
of the steel roof deck and to the side of
blocking in between OWSJ bearing
seats. Connect the blocking to existing
nailer plates on top of the steel beams.
4.4
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August 28, 2013
Item
Seismic Deficiency
Retrofit Concept
4.5
There is a lack of diaphragm
continuity around diaphragm offsets in
the lower roof.
Install drag struts/chords at offset
locations on the underside of the roof
diaphragm.
Walls
4.6
4.7
The walls between the Stage and the
Gym and the back of the Stage have
inadequate shear capacity.
Concrete block walls are typically only
anchored to the foundation at pilaster
locations. Anchorage is insufficient.
Install a new concrete buttress wall on
the exterior of the building.
At the roof level, install a continuous drag
strut connected to the roof diaphragm
and each of the concrete buttress walls.
At all concrete block walls, upgrade
anchorage to existing foundations by
opening up vertical slots in the base of
the wall, installing new foundation
dowels, and grouting the slotted wall
cells.
Main Floor
4.8
Foundations
4.9
There is no existing foundation for
new exterior concrete buttress walls.
Install new concrete foundations with soil
anchors at new concrete buttress
locations.
4.10
At the two new interior plywood
shearwalls on the northeast side of
the Gym, the existing slab capacity is
inadequate for the new shearwalls.
Install a new under-slab grade beam
continuous between the Gym wall and
the exterior wall at the end of the
shearwall.
4.11
There’s a concrete block wall
between the Lobby and Kitchen at the
northeast corner of the Gym that is
unsupported at its top.
Anchor the top of the concrete wall to
the roof diaphragm.
4.12
The concrete block firewall along the
edge of Block Two is not
unsupported at its top.
Anchor the top of the concrete wall to
the roof diaphragm of Block Two.
4.13
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to construction.
9
SELKIRK ELEMENTARY
5.0
August 28, 2013
FINDINGS




There are various seismic deficiencies in Block One. The shearwalls, roof
diaphragm and floor diaphragms all contain seismic deficiencies that require
upgrading, including inadequate strength, stiffness and load path connections. The
brick chimney is a non-structural heavy falling hazard.
In Block 2, seismic deficiencies are primarily associated with the roof diaphragm.
The non-ductile welded steel deck roof diaphragm has inadequate shear capacity,
inadequate load paths to perimeter shearwalls, and lack of detailing to handle
diaphragm discontinuities.
In Block 3, the non-ductile steel deck roof diaphragm has long spans and
inadequate load paths, anchorage to perimeter walls, and detailing to handle stress
concentrations at diaphragm offsets. The walls are a mixed system of concrete
block masonry and plywood shearwalls. Concrete block walls are only partially
grouted and reinforced, although they don’t meet minimum requirements for
reinforcing in seismic zones. There is inadequate anchorage of the concrete block
walls to the foundation.
DNA 5143/5144
10
SELKIRK ELEMENTARY
6.0
August 28, 2013
below:
Selkirk Elementary Seismic Upgrading
Item
Block 1
Block 2
Block 3
Total
Construction Year
1958
1972
1978
-
Description
Original
Addition
Addition
-
Total Area
17,184 sf
12,844 sf
13,403 sf
43,431 sf
$54,820
$252,290
$226,830
$533,940
Upper Floor
$24,720
$0
$0
$24,720
Main Floor7
$0
$0
$0
$0
$74,660
$0
$150,090
$224,750
Foundations
$0
$0
$149,800
$149,800
Miscellaneous and
Non-Structural7
$10,000
$0
$11,550
$21,550
Subtotal 1
$164,200
$252,290
$538,270
$954,760
$29,556
$45,412
$96,889
$171,857
Hazardous Materials
($10/sf)
$171,835
$128,440
$130,435
$430,710
Subtotal 2
$365,591
$426,142
$765,593
$1,557,326
Contractor Overhead
and Profit (20%)
$73,118
$85,228
$153,119
$311,465
Construction
Contingency (20%)
$73,118
$85,228
$153,119
$311,465
Consultant Fees
(15%)6
$65,806
$76,706
$137,807
$280,319
Total
$577,634
$34 / sf
$673,305
$52 / sf
$1,209,637
$93 / sf
$2,460,576
$57 / sf
Roof7
7
7
Walls
7
Note:
4. The cost estimate is an ASTM Class 4 Cost Estimate with an expected accuracy
between +30% and -20% for a project that is defined up to 15% complete. No
drawings are developed as part of this cost estimate.
5. The cost estimate does not include soft costs, such as taxes, moving costs,
temporary facilities, loss of use/revenue, etc.
6. Consultant fees are calculated as a percentage of the subtotal of all elements except
the construction contingency.
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SELKIRK ELEMENTARY
APPENDIX A
Block Plan
DNA 5143/5144
August 28, 2013
NORTH
SELKIRK ELEMENTARY
APPENDIX B
Photographs
DNA 5143/5144
August 28, 2013
SEIS
SMIC EVALU
UKON SCHO
OOLS
SEL
LKIRK ELEM
MENTARY
Block One no
ortheast elevaation
Block Two north elevatio
on
A 5143/5144
4
DNA
August 28
8, 2013
SEIS
SMIC EVALU
UKON SCHO
OOLS
SEL
LKIRK ELEM
MENTARY
Block Threee south elevation
Block Threee north elevatio
on
A 5143/5144
4
DNA
August 28
8, 2013
SEIS
SMIC EVALU
UKON SCHO
OOLS
SEL
LKIRK ELEM
MENTARY
August 28
8, 2013
Concrete blo
ock wall at so
outhwest corner of Block Tw
wo
A 5143/5144
4
DNA
SEIS
SMIC EVALU
UKON SCHO
OOLS
SEL
LKIRK ELEM
MENTARY
Brick chimneey in Block One
A 5143/5144
4
DNA
August 28
8, 2013
SEIS
SMIC EVALU
UKON SCHO
OOLS
SEL
LKIRK ELEM
MENTARY
Block One
e attic roof fraaming in one-sstorey section
n
Block O
One corridor
A 5143/5144
4
DNA
August 28
8, 2013
SEIS
SMIC EVALU
UKON SCHO
OOLS
SEL
LKIRK ELEM
MENTARY
Block On
ne classroom
Block Tw
Two corridor
A 5143/5144
4
DNA
August 28
8, 2013
SEIS
SMIC EVALU
UKON SCHO
OOLS
SEL
LKIRK ELEM
MENTARY
Block Two
o roof structuree
Block Th
hree corridor
A 5143/5144
4
DNA
August 28
8, 2013
SEIS
SMIC EVALU
UKON SCHO
OOLS
SEL
LKIRK ELEM
MENTARY
Block Thre
ee roof structu
ure connectio
on to gym wall
Block
B
Three lo
ower roof struccture
A 5143/5144
4
DNA
August 28
8, 2013
SEIS
SMIC EVALU
UKON SCHO
OOLS
SEL
LKIRK ELEM
MENTARY
Block thre
ee lower roof structure at p
perimeter wall
Block Threee gymnasium
m
A 5143/5144
4
DNA
August 28
8, 2013
SEIS
SMIC EVALU
UKON SCHO
OOLS
SEL
LKIRK ELEM
MENTARY
Block
B
Three g
gym roof struccture
A 5143/5144
4
DNA
August 28
8, 2013
SELKIRK ELEMENTARY
August 28, 2013
APPENDIX C
Building System
DNA 5143/5144
TA
AKHIN
NI ELEM
MENT
TARY
SE
EISMIC EV
VALUATION
OF
F VARIOU
US YUKO
ON SCHOOLS
Aug
gust 28, 2013
Yukon schools.
DNA
A 5143/5144
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TAKHINI ELEMENTARY
August 28, 2013
TABLE OF CONTENTS
1.0
2.0
3.0
4.0
5.0
6.0
BLOCK ONE – 1960 CLASSROOM
BLOCK TWO – 1960 GYMNASIUM
FINDINGS
3
3
7
8
9
10
APPENDICES
Appendix A
Appendix B
Appendix C
DNA 5143/5144
Block Plan
Photographs
System
2
TAKHINI ELEMENTARY
1.0
August 28, 2013
Takhini was originally constructed in 1960 with a one-storey administrative section between
a two-storey classroom wing and a gymnasium. In 1984, there was a boiler room addition
to the north, and in 1988, there was a one-storey classroom addition to the west. For
evaluation purposes, the school is spilt into three blocks.
2.0
BLOCK ONE – 1960 CLASSROOM
The roof structure above the two-storey classroom wing consists of 1” thick horizontal
shiplap on 2x4 purlins spaced at 16” on centre supported by wood trusses and columns
at 4’-0” on centre. The roof above the one-storey administrative section is built with
dimensional lumber rafters on unbraced wood stud pony walls in the attic and by
perimeter and interior stud walls below the ceiling.
The upper floor structure in the two-storey classroom wing consists of a 5/16” plywood
subfloor on 1” thick T&G sheathing and 3x14 wood joists spaced at 16” on centre above
the 24’-3” wide classrooms and 2x8 wood joists spaced at 16” on centre above the 9’-6”
wide corridor. Upper floor joists are supported by wood headers and columns around the
perimeter and by 2x6 stud walls along the corridor.
The main floor structure above the crawl space is similar to that of the upper floor;
however, 2x8 floor joists spaced at 16” on centre span across 2x4 and 2x6 unbraced
pony walls spaced at less than 12’-0” on centre.
Perimeter foundations are typically 8” thick reinforced concrete foundation walls on 2’-0”
wide x 1’-0” thick reinforced concrete footings. Interior pony walls are typically supported
by reinforced concrete footings above the crawl space skim coat.
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3
TAKHINI ELEMENTARY
Item
August 28, 2013
Seismic Deficiency
Retrofit Concept
The shiplap sheathing roof diaphragm
in the two-storey classroom section
has a relatively high aspect ratio and
does not have adequate strength or
stiffness in the east-west direction.
Upgrade roof diaphragm by installing
new plywood sheathing on top.
Roof
2.1
Introduce new shearwalls inside the
building to reduce the demand on the
roof diaphragm.
Within the attic, install new plywood
shearwalls directly above new shearwalls
in the upper floor. Connect the new attic
shearwalls to the roof diaphragm and
shearwall below.
2.2
There are inadequate load path
diaphragm and the new interior
shearwalls.
Within the attic in the north-south
direction, install two continuous drag
struts underside the roof diaphragm
parallel to shearwalls along the corridor
by doubling an existing 2x4 joist line with
new 2x4s and installing light gauge metal
strap ties to create continuous splices.
Fasten the 2x6s together and connect to
the roof diaphragm At attic shearwall
locations, connect the drag strut to the
new plywood shearwalls.
Within the attic in the east-west direction,
install new drag struts across the width
of the roof at new plywood shearwall
locations. Install double 2x4 blocking
between existing 2x4 roof purlins and
connect the blocking to the roof
diaphragm. On the underside of the
blocking, install continuous light gauge
metal straps.
At new shearwall
locations, connect the drag strut to the
shearwall.
Upper Floor
2.3
The shiplap sheathing diaphragm has
a relatively high aspect ratio and does
not have adequate capacity or
stiffness in the east-west direction.
DNA 5143/5144
Introduce new shearwalls inside the
building to reduce the demand on the
upper floor diaphragm.
4
TAKHINI ELEMENTARY
Item
Seismic Deficiency
August 28, 2013
Retrofit Concept
Within the upper floor, at new shearwall
locations, install solid blocking within the
joist space and connect to the new
shearwalls above and below.
2.4
connections between the upper floor
diaphragm and the new interior
shearwalls.
In the north-south direction, install two
continuous drag struts underside the
upper floor diaphragm parallel to
shearwalls along the corridor. On the
classroom side on each side of the
corridor, remove ceiling finishes to
access the underside of the floor
structure adjacent to the corridor wall.
Install solid blocking between each joist
and connect the blocking to the floor
diaphragm.
Install continuous light
gauge metal straps on the underside of
the blocking.
Drag struts to be
continuous from one end of the building
to the other.
In the east-west direction, install new
drag struts across the width of the upper
floor at new plywood shearwall locations.
Add double joists at shearwall locations
and splice across the corridor. Connect
the drag strut to the new shearwalls.
Open the ceiling from the underside to
gain access to the floor structure and
repair once complete.
Main Floor
2.5
The existing main floor diaphragm is
being relied upon to transfer lateral
loads from interior shearwalls above
to perimeter concrete foundations, as
the shearwalls above the main floor
are not continuous to the foundation.
The main floor diaphragm has
inadequate capacity to transfer these
loads.
Install new plywood shearwalls within the
crawl space directly beneath new
shearwalls above the main and upper
floors.
2.6
Along the north wall of the original
two-storey classroom, parallel to floor
joists,
out-of-plane
connections
between the main floor diaphragm
and the concrete foundation wall are
inadequate
for
seismic
earth
pressures on the foundation wall.
Install blocking between 3 bays of floor
joists at 4’-0” on centre. Connect the
blocking to the floor diaphragm and
foundation wall.
DNA 5143/5144
5
TAKHINI ELEMENTARY
Item
Seismic Deficiency
August 28, 2013
Retrofit Concept
Walls
2.7
2.8
The existing walls consist of drywall
sheathed wood stud walls along the
corridors and drywall or wood, let-in
diagonally braced wood stud walls
between rooms. These walls do not
continue past the upper floor ceiling
up to the roof diaphragm, and they
do not continue below the main floor
level down to the foundation. These
walls have inadequate strength and
low ductility.
connections between shearwalls
above and below the main floor.
Upgrade a series of existing solid wall
segments by removing the existing wall
finishes and installing plywood on one
side of the walls. Upgrade load path
connections at the top and bottom of the
walls. Reinstall wall finishes.
In the north-south direction, upgrade
several wall segments along the corridor
from the classroom side where possible.
In the east-west direction, upgrade walls
on one side of the stairwell, in addition to
other selected walls throughout the
building.
All upgraded walls shall be installed
continuous from the foundation in the
crawl space all the way up to the roof
diaphragm in the attic.
Upgrade load path connections by
installing blocking between floor joists at
shearwall locations and connecting the
blocking to shearwalls above and below.
Foundations
2.9
Existing interior strip footings in the
crawl
space
have
inadequate
overturning capacity for upgraded
plywood shearwalls.
Install mass footings at each end of the
new shearwalls in the crawl space.
2.10
2.11
The front entrance canopy has
inadequate strength and stiffness.
There is inadequate ground cover in
some of the post bases leading to
wood deterioration.
At the canopy at the northeast corner
of the block, post base connections
are inadequate.
DNA 5143/5144
Install a new steel moment frame and
foundations at the front of the canopy
connected
to
the
canopy
roof
diaphragm. Upgrade the connection of
the canopy beams to the roof structure.
Install new post bases with high concrete
pedestals.
Remove existing post base connections.
Install concrete pedestals and new post
base connections.
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TAKHINI ELEMENTARY
August 28, 2013
Item
Seismic Deficiency
Retrofit Concept
2.12
At the entrance canopy at the west
end of the administrative wing, post
base connections are inadequate and
some post cap connections are
missing.
Remove existing post base connections.
Install concrete pedestals and new post
base connections. Install new post caps
where required.
2.13
3.0
to construction.
BLOCK TWO – 1960 GYMNASIUM
The roof structure consists of 5/8” plywood on 3x10 and 4x10 purlins spaced at 16” on
centre supported by glulam/steel rod trusses and glulam columns at 16’-0” on centre.
The main floor structure above the crawl space consists of 3/8” plywood subfloor on 3/4”
thick shiplap sheathing and 2x10 wood joists spaced at 16” on centre with spans less than
13’-0”. Floor joists are supported within the gym by unbraced wood stud pony walls on
reinforced concrete strip footings. Around the perimeter of the gym, there are reinforced
concrete foundation walls and strip footings, with reinforced pilasters under the glulam
columns.
Item
Seismic Deficiency
Retrofit Concept
Roof
3.1
Walls
3.2
Along the north gym wall, load path
connections between the shearwalls
and the concrete foundation are
inadequate.
DNA 5143/5144
Within the crawl space, install solid
blocking between joists underneath the
shearwall above connected to the
concrete foundation. Open the base of
the shearwall above from inside the
Gymnasium by removing wall finishes.
Connect the shearwall bottom plate to
the new blocking below and refinish the
base of the wall.
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TAKHINI ELEMENTARY
August 28, 2013
Main Floor
3.3
Parallel to floor joists, out-of-plane
connections between the main floor
diaphragm
and
the
concrete
foundation wall are inadequate for
seismic earth pressures on the
foundation wall.
foundation wall.
Foundations
3.4
3.5
3.6
4.0
Canopy columns are too slender.
Upgrade columns.
to construction.
The roof structure consists of 1/2” plywood on engineered wood trusses spaced at 2’-0”
on centre supported by wood stud walls on the interior and around the perimeter. Interior
corridor walls are sheathed with 5/8” drywall, and perimeter stud walls are sheathed with
1/2" OSB.
The main floor structure above the crawl space consists of 3/4” OSB on 2x10 fir joists
spaced at 16” on centre with spans less than 14’-6”. Floor joists are supported within the
gym by unbraced wood stud pony walls within the crawl space and by reinforced concrete
foundation walls and strip footings around the perimeter.
Item
Seismic Deficiency
Retrofit Concept
In the north-south direction along the
east and west walls of the upper roof,
there is an inadequate load path
gable trusses.
Within the attic, install new 2x6 soild
blocking
between
alternate
2x6
outriggers and connect the blocking to
the roof diaphragm and gable truss.
The connection between the lower
roof and the gable wall is unknown.
From within the attic space of the upper
roof, install new blocking in the plane of
the gable truss of the upper roof. From
within the attic of the lower roof, screw
the end truss into the blocking installed
in the attic of the upper roof.
Roof
4.1
4.2
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TAKHINI ELEMENTARY
August 28, 2013
Item
Seismic Deficiency
Retrofit Concept
4.3
The connection between the lower
roof and the Block One wall is
unknown.
Locally remove the wall finishes on the
exterior side of the Block One wall and
the Block Three roof.
Upgrade
connections between the roof and the
wall.
There is inadequate shear capacity
and anchorage in the north and south
perimeter shearwalls.
Remove exterior wall finishes on the
north and south walls. Remove the OSB
sheathing on the three main wall
segments to install new holdown
connections to the foundation. Reinstall
and renail new sheathing.
Install
continuous metal strap ties above and
below the windows.
Walls
4.4
Main Floor
4.5
There is limited bearing of main floor
joists
on
perimeter
concrete
foundation walls and inadequate outof-plane anchorage.
With the crawl space, upgrade the
connection of floor joists to the concrete
foundation wall at 4’-0” on centre.
4.6
Parallel to floor joists, there is
inadequate restraint at the floor
diaphragm level for seismic earth
pressures on the foundation wall.
foundation wall.
4.7
5.0
No miscellaneous upgrades required.
FINDINGS




The most significant seismic deficiencies at Takhini are within Block One, which
consists of a one-storey administrative wing and a two-storey classroom wing.
o The shearwalls, roof diaphragm and floor diaphragms all contain seismic
deficiencies that require upgrading, including inadequate strength, stiffness
and load path connections.
o Interior foundations are inadequate for upgraded shearwalls within the
building.
o There are seismic and condition deficiencies in the exterior canopies.
In Block 2, there are minimal seismic deficiencies. Some diaphragm load path
connections and bracing for seismic earth pressures are required at the main floor
level.
In Block 3, the north and south perimeter walls require remediation from the roof
diaphragm level down to the foundation. The connections between the lower roof
and the upper roof and Block One wall require upgrading. The connections
between the main floor diaphragm and the foundation require upgrading.
DNA 5143/5144
9
TAKHINI ELEMENTARY
6.0
August 28, 2013
below:
Takhini Elementary Seismic Upgrading
Item
Block 1
Block 2
Block 3
Total
Construction Year
1960
1960
1988
-
Description
Classroom
Gym
Addition
-
Total Area
22,580 sf
7,285 sf
3,415 sf
33,280 sf
$183,795
$0
$8,177
$191,972
Upper Floor
$53,100
$0
$0
$53,100
Main Floor7
$43,930
$11,050
$19,527
$74,507
$119,615
$12,000
$35,166
$166,781
Foundations
$63,345
$0
$0
$63,345
Miscellaneous and NonStructural7
$22,500
$0
$0
$22,500
Subtotal 1
$486,285
$23,050
$62,870
$572,205
$87,531
$4,149
$11,317
$102,997
Hazardous Materials
($10/sf)
$225,800
$72,850
$0
$298,650
Subtotal 2
$799,616
$100,049
$74,187
$973,852
Contractor Overhead
and Profit (20%)
$159,923
$20,010
$14,837
$194,770
Construction
Contingency (20%)
$159,923
$20,010
$14,837
$194,770
Consultant Fees (15%)6
$143,931
$18,009
$13,354
$175,294
Total
$1,263,394
$56 / sf
$158,077
$22 / sf
$117,214
$34 / sf
$1,538,686
$46 / sf
Roof7
7
7
Walls
7
Note:
4. The cost estimate is an ASTM Class 4 Cost Estimate with an expected accuracy
between +30% and -20% for a project that is defined up to 15% complete. No
drawings are developed as part of this cost estimate.
DNA 5143/5144
10
TAKHINI ELEMENTARY
APPENDIX A
Block Plan
DNA 5143/5144
August 28, 2013
NORTH
TAKHINI ELEMENTARY
APPENDIX B
Photographs
DNA 5143/5144
August 28, 2013
SEIS
SMIC EVALU
UKON SCHO
OOLS
TAK
KHINI ELEMENTARY
Blo
ock One with Block Two at far left
Blocck Two
A 5143/5144
4
DNA
August 28
8, 2013
SEIS
SMIC EVALU
UKON SCHO
OOLS
TAK
KHINI ELEMENTARY
Blocck One
Blocck Three
A 5143/5144
4
DNA
August 28
8, 2013
SEIS
SMIC EVALU
UKON SCHO
OOLS
TAK
KHINI ELEMENTARY
Blocck Three
Block
B
One fron
nt entrance caanopy
A 5143/5144
4
DNA
August 28
8, 2013
SEIS
SMIC EVALU
UKON SCHO
OOLS
TAK
KHINI ELEMENTARY
Block T
Two canopy
A 5143/5144
4
DNA
August 28
8, 2013
SEIS
SMIC EVALU
UKON SCHO
OOLS
TAK
KHINI ELEMENTARY
Block O
One canopy
Block O
One canopy
A 5143/5144
4
DNA
August 28
8, 2013
SEIS
SMIC EVALU
UKON SCHO
OOLS
TAK
KHINI ELEMENTARY
Block One m
main floor corridor
Block One up
pper floor corrridor
A 5143/5144
4
DNA
August 28
8, 2013
SEIS
SMIC EVALU
UKON SCHO
OOLS
TAK
KHINI ELEMENTARY
Block Two
o gymnasium
Block Thrree classroom
m
A 5143/5144
4
DNA
August 28
8, 2013
TAKHINI ELEMENTARY
August 28, 2013
APPENDIX C
Building System
DNA 5143/5144
WHITEH
W
HORSE
E ELEM
MENTA
ARY
SE
EISMIC EV
VALUATION
OF
F VARIOU
US YUKO
ON SCHOOLS
Aug
gust 28, 2013
Yukon schools.
DNA
A 5143/5144
4
August 28, 2013
TABLE OF CONTENTS
1.0
2.0
3.0
4.0
5.0
BLOCK ONE – ORIGINAL SCHOOL
FINDINGS
3
3
9
12
13
APPENDICES
Appendix A
Appendix B
Appendix C
DNA 5143/5144
Block Plan
Photographs
System
2
1.0
August 28, 2013
Whitehorse Elementary was originally constructed in 1950 as a three storey building that is
U-shaped in plan with classrooms around the perimeter and a gym in the middle. In 1954,
a new classroom wing was added to the southeast end of the school. For the purpose of
this assessment, the school is divided into two blocks.
2.0
BLOCK ONE – ORIGINAL SCHOOL
The roof, upper floor and main floor structures in the U-shaped classroom wing consist of
one-way concrete slabs between 4 and 5 1/2 inches thick. The suspended slabs are
supported by concrete beams and columns in the interior of the building. Around the
perimeter of the building, there are non-ductile concrete moment frames and concrete
shearwalls, which are also located on each side of stairwells.
Above the gym, the roof structure consists of 1 1/2" thick T&G wood decking on 34” deep
steel trusses spaced at 5’-4” on centre. The trusses are supported on concrete beams
and a concrete wall. The floor of the gym consists of diagonal wood shiplap on
dimensional lumber joists supported by non-ductile concrete beams and columns on
spread footings.
On the interior of the building, concrete columns are typically supported by reinforced
concrete spread footings. Around the perimeter of the building; at walls adjacent to
stairwells; and around the interior perimeter of the gym, the foundations consist of
unreinforced concrete foundation walls supported by reinforced concrete strip footings.
Interior partition walls in this block are assumed to be wood-frame with plaster, as there
were no architectural floor plans available for review for Block One,
There’s an expansion joint on the south side of the stairwell in the middle of the building;
however, there is no actual structural separation at the expansion joint.
DNA 5143/5144
3
Item
August 28, 2013
Seismic Deficiency
Retrofit Concept
2.1
The 1 1/2" thick T&G wood decking
diaphragm above the gym does not
have adequate strength or stiffness.
Upgrade the diaphragm by installing a
system of steel cross braces on the
underside of the steel roof joist top
chords.
2.2
There are inadequate load paths
around the perimeter of the 1 1/2"
thick T&G wood decking diaphragm.
Upgrade load paths by installing
continuous steel members around the
perimeter of the gym diaphragm
connected to the new steel braced
diaphragm.
Roof
Upgrade load paths around the
perimeter of the diaphragm as described
above.
2.3
There is inadequate roof diaphragm
reinforcement to tie the gym
diaphragm to the U-shaped concrete
diaphragm and for the U-shaped
concrete diaphragm to handle
stresses at the inside corners.
There are insufficient drag struts to
connect the roof diaphragm to new
and upgraded concrete shearwalls.
Install drag struts in the north-south
direction on each side of the gym. The
drag struts shall be continuous from one
side of the building to the other,
connected to the gym diaphragm; to the
concrete slabs and beams in the
concrete diaphragm; to the concrete wall
on the east side of the gym; and to the
new north-south shearwalls at the north
and south ends of the building.
Install east-west drag struts along one
side of the two east-west corridors in line
with new concrete shearwalls. Drag
struts shall be connected to the
underside of the concrete slab and to the
side of the concrete beam.
On each side of the middle stairwell,
install a continuous drag strut from the
east side of the gym to the west side of
the building, connected to the upgraded
shearwalls on each side of the stairwell.
2.4
between the concrete roof diaphragm
and the three shearwalls to be
retrofitted.
DNA 5143/5144
Upgrade load paths by installing a new
concrete collector on the underside of
the slab at the top of the retrofitted
shearwalls.
4
August 28, 2013
Upper Floor
2.5
There is inadequate upper floor
diaphragm reinforcement for the Ushaped concrete diaphragm to
handle stresses at the inside corners
of the U-shaped diaphragm.
connect the upper floor diaphragm to
new
and
upgraded
concrete
shearwalls.
direction on each side of the gym at the
upper floor level. The drag struts shall be
continuous from one side of the building
to the other, connected to the east gym
wall; to the concrete slab and beam on
the west side of the gym; to the concrete
diaphragm; and to the new north-south
concrete shearwalls at the north and
south ends of the building.
side of the two east-west corridors in line
with new concrete shearwalls. Drag
struts shall be connected to the
underside of the concrete slab and to the
side of the concrete beam.
On each side of the middle stairwell,
install a continuous drag strut from the
east side of the north-south corridor to
the west side of the building, connected
to the upgraded shearwalls on each side
of the stairwell and to the floor
diaphragm.
2.6
At the stairwell opening, there are
insufficient collectors to transfer
diaphragm stresses.
2.7
connections between the upper floor
diaphragm and new and retrofitted
shearwalls.
DNA 5143/5144
Install east-west drag struts as note
above.
On the east side of the stairwell opening,
install a north-south collector on the
underside of the floor diaphragm
extending beyond the stairwell opening.
Upgrade load paths between the
concrete diaphragm and shearwalls from
the underside.
5
August 28, 2013
Main Floor
2.8
The
diagonal
wood
shiplap
diaphragm in the gym floor does not
have adequate strength or stiffness,
and it is supporting a series of nonductile concrete columns and beams.
Upgrade the diaphragm and concrete
beam/column bracing by installing a
system of steel cross braces on the
underside of the concrete beams.
2.9
around the perimeter of the wood
shiplap diaphragm.
Upgrade load paths by installing
continuous steel angles around the
perimeter of the gym diaphragm
connected to the new steel braced
diaphragm.
Upgrade load paths around the
perimeter of the diaphragm as described
above.
2.10
There is inadequate main floor
diaphragm reinforcement to tie the
gym diaphragm to the U-shaped
concrete diaphragm and for the Ushaped concrete diaphragm to
handle stresses at the inside corners.
connect the main floor concrete
diaphragm to new and upgraded
concrete shearwalls.
direction on each side of the gym. The
drag struts shall be continuous from one
side of the building to the other,
connected to the gym diaphragm; to the
concrete slabs and beams in the
concrete diaphragm; and to the concrete
shearwalls.
side of the two corridors in line with the
new concrete shearwalls. Drag struts
shall be connected to the underside of
the concrete slab and to the side of the
concrete beam.
In line with the concrete shearwalls in the
east-west direction on each side of the
stairwell, install a continuous drag strut
from the west side of the building to
beyond the east side of the corridor.
2.11
At the stairwell opening, there are
insufficient collectors to transfer
diaphragm stresses.
2.12
connections between the main floor
diaphragm and new and retrofitted
shearwalls.
DNA 5143/5144
Install east-west drag struts as noted
above.
On the east side of the stairwell opening,
install a north-south collector on the
underside of the floor diaphragm
extending beyond the stairwell opening.
Upgrade load paths between the
concrete diaphragm and shearwalls from
the underside.
6
August 28, 2013
Walls
Throughout the building there are a
limited number of randomly placed
concrete shearwalls, and there are
typically poor load path connections
between the diaphragms and these
walls, particularly to walls around
stairwell openings.
2.13
Throughout the interior of the building
and around the perimeter of the
building, there is a series of nonductile concrete beams and columns.
In the east-west direction, these nonductile frames are the primary lateral
system for the building.
The shape of the building and
distribution of shearwalls, moment
frames and diaphragm types make
this a torsionally sensitive structure.
2.14
There is a stiffness irregularity in the
perimeter walls, as the columns in the
lower story are shorter than those in
the upper story due to the height of
the basement retaining walls.
Reduce the ductility demand on the
frames by installing new concrete
shearwalls connected to the diaphragms
and/or foundation at the top and bottom,
along with drag struts along the length of
the building to drag load from the
diaphragms into the new shearwalls.
New/retrofitted shearwalls shall be
continuous from the foundation to the
roof.
In the north-south direction, upgrade the
two existing concrete shearwalls on the
west side of the two eastern stairwells.
Also, install two new concrete shearwalls
in line with the west side of the gym.
In the east-west direction, install a total
of four new concrete shearwalls. Along
the northern corridor, install a new
shearwall at each end on the north side
of the corridor. Along the southern
corridor, install a new shearwall at each
end on the south side of the corridor.
Also, upgrade the two existing
shearwalls on each side of the middle
stairwell.
Reinforce the existing lower floor
columns around the perimeter of the
building.
Foundations
2.15
At the six new concrete shearwalls,
there are no existing adequate
foundations
upon
which
the
shearwalls can be located. The soil
bearing capacity under new footings
will not be adequate for a reasonably
sized footing.
Install new concrete grade beam footings
under new concrete shearwalls. Anchor
the grade beams with soil anchors at
each end for sliding and overturning.
2.16
At the four retrofitted concrete
shearwalls, the existing strip footings
and bearing soil underneath do not
have adequate capacity.
From inside the building, cut open the
floor and install, new a new concrete
grade beam with soil anchors at each
end for sliding and overturning.
DNA 5143/5144
7
2.17
Perimeter
unreinforced
concrete
foundation walls are partially retaining
soil (approximately 4 ft soil imbalance)
on the exterior of the building, and
they are subjected to seismic earth
pressures.
August 28, 2013
Install a structural steel back-up system
on the interior side of the wall.
2.18
There is an expansion joint in the
middle of the building running in the
east-west direction.
There is no
actual structural separation at the
joint. Concrete elements on each
side of the joint butt into each other.
At the main floor and roof levels
above the gym, the wood diaphragms
are continuous across the joint. The
wood diaphragms do not have
enough tensile capacity to tie the
concrete sections of the building on
each side of the expansion joint
together. As a result, there could be
structural damage to the roof and
floor diaphragms, which could affect
their gravity load-carrying capability.
The sections of the building on each
side of the joint will act independently.
There could be pounding and
damage between the two sections of
the building at the expansion joint.
This is of particular concern at the
middle stairwell, where the floors of
the southern section intersect the wall
on the south side of the stairwell at
mid-height between landings.
2.19
The brick chimney is a potential falling
hazard.
Connection details are
unknown.
2.20
the Block.
DNA 5143/5144
Eliminate this expansion joint and
structurally connect the two sections of
the building together.
At the vertical expansion joint in the wall
on the east side of the gym, connect the
concrete pilaster together on each side
of the joint. At the roof and main floor
levels, install a continuous drag strut
from one side of the building to the other,
across the expansion joint.
At the east-west expansion joint south of
the stair, from the underside of the slab
at the floor and roof levels, connect the
double concrete wall together by drilling
through the wall and installing continuous
horizontal plates on each side of the wall
and drilling epoxy dowels through each
wall connected to the steel plates on
each side. At the roof and main floor
levels, install a continuous drag strut
from the east side of the gym to the west
side of the building, connected to the
concrete shearwall. Above the corridor,
fasten the drag strut to each side of the
expansion joint.
Remove the brick chimney and replace
with a new flue and light framing.
to construction.
8
3.0
August 28, 2013
The roof, upper floor and main floor structures in Block Two consist of one-way concrete
slabs between 4 and 5 inches thick. The suspended slabs are supported by concrete
beams above classrooms and by concrete walls on each side of the corridor and stairwell.
Around the perimeter of the building, there are non-ductile concrete moment frames and
concrete shearwalls.
On the interior of the building, concrete columns are typically supported by reinforced
concrete spread footings. Around the perimeter of the building, the foundations consist of
unreinforced concrete foundation walls supported by reinforced concrete strip footings.
On the interior of the building, concrete walls are typically reinforced all the way down to
reinforced concrete strip footings.
There are two expansion joints shown in this block in the north-south direction. One is
located at the junction with the existing building, while the other is located approximately in
the middle of the block. The latter expansion joint only extends halfway through the width
of the building.
Item
Seismic Deficiency
Retrofit Concept
3.1
Based on the assumption that there
was a construction joint at the top of
the wall and the underside of the roof
slab, there are inadequate shear load
paths between the roof diaphragm
and the corridor shearwalls and the
western shearwall.
Upgrade shear load paths by installing
continuous steel angles on the underside
of the slab and into the side of the
concrete walls.
Special splices are
required across corridor concrete
beams.
3.2
There are inadequate north-south
drag struts in the slab at the two
middle concrete shearwalls.
Install a continuous drag strut across the
width of the building on the underside of
the slab parallel to the two north-south
shearwalls.
3.3
At the plan offset at the south end of
the building, there is inadequate
anchorage tying together the adjacent
sections of diaphragm.
Install
an
underslab
drag
strut
approximately 24 ft long two splice the
two sections of diaphragm together at
the perimeter walls.
Roof
DNA 5143/5144
9
August 28, 2013
Upper and Main Floors
3.4
There are inadequate north-south
drag struts in the slab at the two
middle concrete shearwalls.
Install a continuous drag strut across the
width of the building on the underside of
the slab parallel to the two north-south
shearwalls.
3.5
In the two floors, there is inadequate
reinforcement in the diaphragms at
the stairwell openings.
In the north-south direction, on the west
side of the stairwell, install a continuous
drag strut on the side of the existing
concrete beam each side of the corridor
and across the corridor.
3.6
At the plan offset at the south end of
the building, there is inadequate
anchorage tying together the adjacent
sections of diaphragm.
Install
an
underslab
drag
strut
approximately 24 ft long two splice the
two sections of diaphragm together at
the perimeter walls.
Concrete
moment
frames
are
considered to be non-ductile based
on reinforcement detailing of columns
and beams.
Utilize concrete moment frames as
gravity load supporting members only.
Use the existing concrete shearwalls as
the defined lateral system of the building,
upgrading them where required. Limit
building deflections to prevent premature
failure of moment frame columns and
beams.
Walls
3.7
Foundations
3.8
There is no distributed reinforcement
in perimeter foundation walls.
In the three north-south, 26 ft long
perimeter foundation walls, install a
reinforced concrete overlay on the
exterior side of the wall.
Improve
connections between the new wall and
the existing shearwall above.
3.9
Perimeter foundation walls are
partially retaining soil (approximately 4
ft soil imbalance) on the exterior of the
building, and they are subjected to
Install a structural steel back-up system
on the interior side of the wall.
3.10
At the junction with the original
building, the footing for the Block 2
wall is bearing on the footing for the
Block 1 wall.
As part of the structural separation
retrofit at the existing expansion joint,
install a new footing at level grade with
the Block One footing. Connect the two
footings together.
DNA 5143/5144
10
3.11
The footings under the north-south
shearwalls walls are not adequate to
prevent bearing capacity failures in
the underlying soil.
August 28, 2013
Install enlarged grade beams on the
exterior side of the footing connected to
the footing and foundation wall.
3.12
3.13
3.14
There is an expansion joint in the
north-south direction shown at the
junction with the existing building;
however, there is no actual structural
separation between the two blocks.
There’s an expansion joint in the
north-south direction between a
double concrete wall west of the
stairwell. The expansion joint does
not extend through the entire width of
the building, and there is no actual
structural separation across the
expansion joint.
the Block.
DNA 5143/5144
Eliminate the expansion joint and
structurally connect the two sections of
the building together.
At the roof and floor levels, from the
underside of the slab, connect the
double concrete wall together by drilling
through the wall and installing continuous
horizontal plates on each side of the wall
and drilling epoxy dowels through each
wall connected to the steel plates on
each side.
Install a drag strut in the east-west
direction as described in the diaphragm
sections relating to the diaphragm plan
offset.
to construction.
11
4.0
August 28, 2013
FINDINGS
















4.1 – Block One
There are several aspects of the original building construction that impact its
potential seismic performance.
The building has an irregular, torsionally sensitive shape, consisting of a U-shaped
concrete diaphragm infilled with weak wood frame diaphragms above the gym at
two of the three stories.
There’s an east-west expansion joint located in the middle of the building that
could instigate roof and main floor wood diaphragm failures; pounding between
adjacent sections of the building on each side of the joint; and failure of the wall on
the south side of the middle stairwell, which is a primary means of egress in the
building.
There are a limited number of randomly placed concrete shearwalls throughout the
building with poor load path connections from the concrete diaphragms.
The concrete moment frames are non-ductile.
There’s a stiffness irregularity in the lower floor due to the short concrete perimeter
columns.
The unreinforced masonry chimney is a potential non-structural falling hazard.
4.2 – Block Two
In Block Two, there is a substantial amount of shearwalls relative to the size of the
Block, and concrete shearwalls exist in both directions. Concrete moment frames
are used primarily for gravity load-carrying purposes.
At roof and floor diaphragms, there is inadequate reinforcement at a few critical
locations, including the stairwell opening, at the southern plan offset, and:
o At the roof level, there are inadequate shear load paths between the
diaphragm and north-south shearwalls, based on assumed construction
details.
o In the north-south direction, there is inadequate reinforcement in the
diaphragm to drag load between isolated shearwalls.
There are two expansion joint locations in this Block with inadequate structural
separation in the joint and discontinuities in the joint through the building.
Foundation walls are typically unreinforced, and existing strip footings under northsouth concrete shearwalls are typically insufficient.
Wall construction is typically concrete shearwall or moment frame.
o Concrete shearwalls typically satisfy minimum reinforcing requirements for
walls to avoid being classified as non-ductile; however, the walls typically
lack adequate boundary reinforcing elements. There is inadequate
boundary tension anchorage to the foundation.
o Concrete moment frames are non-ductile and are governed by the
capacity of the columns, which are also the primary load-carrying support
members. Concrete moment frames typically have inadequate capacity
and stiffness, where drag struts are inadequate to carry load into existing
shearwalls.
DNA 5143/5144
12
5.0
August 28, 2013
below:
Whitehorse Elementary Seismic Upgrading
Item
Block 1
Block 2
Total
Construction Year
1950
1954
-
Description
Original
Addition
-
Total Area
63,335 sf
17,868 sf
81,203 sf
$251,880
$30,000
$281,880
$276,600
$37,200
$313,800
$374,080
$37,200
$411,280
$711,250
$35,000
$746,250
$780,000
$237,990
$1,017,990
$54,000
$64,800
$118,800
Subtotal 1
$2,447,810
$442,190
$2,890,000
$440,606
$79,594
$520,200
$633,350
$178,680
$812,030
Subtotal 2
$3,521,766
$700,464
$4,222,230
$704,353
$140,093
$844,446
$704,353
$140,093
$844,446
$633,918
$126,084
$760,002
$5,564,390
$88 / sf
$1,106,733
$62 / sf
$6,671,124
$82 / sf
Roof7
Upper Floor
7
Main Floor7
7
Walls
Foundations7
7
Total
6
Note:
1. This cost estimate shall be read in conjunction with DNA’s report on the Seismic Evaluation
of Various Yukon Schools (August 28, 2013).
4. The cost estimate is an ASTM Class 4 Cost Estimate with an expected accuracy between
+30% and -20% for a project that is defined up to 15% complete. No drawings are
developed as part of this cost estimate.
DNA 5143/5144
13
APPENDIX A
Block Plan
DNA 5143/5144
August 28, 2013
NORTH
APPENDIX B
Photographs
DNA 5143/5144
August 28, 2013
SEIS
SMIC EVALU
UKON SCHO
OOLS
WHITEHORSE ELEMENTAR
E
RY
South Elevation
East Elevation
A 5143/5144
4
DNA
August 28
8, 2013
SEIS
SMIC EVALU
UKON SCHO
OOLS
E
RY
Northeaast Elevation
Northweest Elevation
A 5143/5144
4
DNA
August 28
8, 2013
SEIS
SMIC EVALU
UKON SCHO
OOLS
E
RY
Concre
ete beam and column under Gym floor
A 5143/5144
4
DNA
August 28
8, 2013
SEIS
SMIC EVALU
UKON SCHO
OOLS
E
RY
August 28
8, 2013
Concrete wa
all and pilasterr in basement under Gym flo
oor
Gym flo
oor framing at basement co
oncrete wall
A 5143/5144
4
DNA
SEIS
SMIC EVALU
UKON SCHO
OOLS
E
RY
Concrete w
wall in basemeent
Crracks in concrrete basementt walls
A 5143/5144
4
DNA
August 28
8, 2013
SEIS
SMIC EVALU
UKON SCHO
OOLS
E
RY
Block One baasement corridor
A 5143/5144
4
DNA
August 28
8, 2013
SEIS
SMIC EVALU
UKON SCHO
OOLS
E
RY
Basemen
nt classroom
A 5143/5144
4
DNA
August 28
8, 2013
SEIS
SMIC EVALU
UKON SCHO
OOLS
E
RY
Basemeent stairwell
A 5143/5144
4
DNA
August 28
8, 2013
SEIS
SMIC EVALU
UKON SCHO
OOLS
E
RY
Block One m
main floor corridor
Main flo
oor corridor
A 5143/5144
4
DNA
August 28
8, 2013
SEIS
SMIC EVALU
UKON SCHO
OOLS
E
RY
Main Floo
or classroom
Block On
ne main entry
A 5143/5144
4
DNA
August 28
8, 2013
SEIS
SMIC EVALU
UKON SCHO
OOLS
E
RY
Bloc
ck One gymn asium – lookin
ng east
Bloc
ck One gymnaasium – lookin
ng south
A 5143/5144
4
DNA
August 28
8, 2013
SEIS
SMIC EVALU
UKON SCHO
OOLS
E
RY
Framing
g above storaage rooms in g
gymnasium
Upper fl oor corridor
A 5143/5144
4
DNA
August 28
8, 2013
SEIS
SMIC EVALU
UKON SCHO
OOLS
E
RY
Typical
T
concreete roof overh
hang
A 5143/5144
4
DNA
August 28
8, 2013
SEIS
SMIC EVALU
UKON SCHO
OOLS
E
RY
Exxpansion joint in east wall o
of gym
A 5143/5144
4
DNA
August 28
8, 2013
SEIS
SMIC EVALU
UKON SCHO
OOLS
E
RY
Exxpansion joint in east wall o
of gym
A 5143/5144
4
DNA
August 28
8, 2013
SEIS
SMIC EVALU
UKON SCHO
OOLS
E
RY
August 28
8, 2013
Joint between
b
Bloc
ck One and Blo
ock Two on n
north side of B
Block Two
A 5143/5144
4
DNA
August 28, 2013
APPENDIX C
Building System
DNA 5143/5144

Seismic evaluation of various Yukon schools [16.75 MB ]

Transcription

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