Walers and Struts

MGF TECHNICAL FILE
TRENCH SHEETS
MGF stock an extensive range of hot rolled
U Piles including Arcelor Mittal and Hoesch,
making us the largest independent stockist in
the UK.
5.2.6
Issue 2
Tel. 01942 402 704
Simple to assemble, two sided, hydraulic bracing system designed to be used with steel trench sheets to
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support trench widths of 0.6m to 3.8m and is normally installed using excavators. MGF also provide Vertishore,
a light weight hydraulic system used to brace small trenches vertically.
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attached to the hydraulic struts using simple pin and retaining clip assemblies. Each strut contains a hydraulic
ram with between 300mm and 670mm of stroke. Connecting the rams (via hydraulic hoses) to an MGF hand
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easily adjusted to suit the excavation dimensions. Once the trench frames are fully assembled and located
at the correct line and level, the rams are pre-loaded against the trench sheets using a hydraulic pump. Preloading of the legs ensures the frame cannot slip and minimises the extent of potential ground movements. Self
sealing quick release valves and mechanical isolation valves ensure that the hydraulic ram pressure cannot
be accidently released once installed. Handling and restraining points are provided on each waler to assist
assembly / removal and to allow the brace to be supported off MGF restraining chains attached to the trench
sheets by hooks.
WALERS AND STRUTS
MGF TECHNICAL FILE
Description
MGF can supply the systems with a full range of suitable handling and restraining chains, Edgesafe edge
protection panels, Endsafe end protection panels and struts, Laddersafe access platforms and pole ladders,
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Manufactured and designed in accordance with BS EN 14653:2005 PARTS 1 and 2 Manually operated Shoring
Systems for Groundwork Support and BS 5975 (2008) Code of Practice for Temporary Works Procedures and
the Permissible Stress Design of Falsework.
Product Notes
1. Waler and trench strut systems should only be installed and removed by competent persons in accordance
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can be located at a variety of positions along the length of the waler. The exact location of the struts will
determine the strength of the waler system.
2. Installation is normally carried out by lowering the assembled frame to the correct installation level and preORDGLQJHDFKVWUXWLQWXUQWRHQVXUHWKDWWKHIUDPHLVSUHVVHG¿UPO\DJDLQVWWKHWUHQFKVKHHWVDQGFDQQRW
slip. Max pre-load pressure of 100Bar (1500psi) must not be exceeded.
3. Restraining chains are hung off the trench sheets and attached to the waler to assist assembly / removal
of the frame and ensure vertical support is provided at all times. All the supplied restraining chains should
be installed (min 2 per waler) and adjusted to ensure an even vertical load distribution. Restraining chains
should never be used for lifting nor solely relied upon to suspend loads above
personnel.
4. Ensure all hydraulic ram isolation valves are closed and all strut pins in place
and secured using the retaining clips provided prior to commencing works.
5. Individual walers and struts should be visually inspected for damage,
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6. Walers and struts should always be installed square and plumb to the
excavation walls ensuring contact with all the inward facing trench sheet
pans. If this is not possible any gaps must be securely packed by using
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7. Safe access/egress, edge protection (for personnel) and barrier
protection (for plant) should always be considered.
8. Prior to removal of systems all hydraulic rams must be released and
retracted to avoid the need for excessive extraction forces and to
avoid damaging the struts.
9. No matter how much care is taken during the installation
and removal of waler and strut trench systems some
ground movement will occur in the areas immediately
surrounding the excavation. Great care must be taken
when specifying these systems for use adjacent to
existing structures and services.
10. Ends of trench runs should always be battered back at a safe
angle or end protection panels/struts installed (see section 6).
design@mgf.ltd.uk
5.3.1
5.
Issue
Issu 2
MGF TECHNICAL FILE
WALERS AND STRUTS
MGF Edgesafe - See
Section 6
MGF Pole Ladder
MGF Laddersafe See Section 6
MGF Endsafe Panel See Section 6
MGF Steel
Walers
5.3.2
Issue 2
MGF Trench Sheets See Section 5.2
Tel. 01942 402 704
WALERS AND STRUTS
MGF TECHNICAL FILE
Handling Point
WLL = 2.0t
Walers are lifted and handled by
attaching MGF lifting chains to the
handling/restraining points as shown.
Waler Strut Connection Detail
Waler struts are connected to the
waler via a pin and retaining clip
detail.
design@mgf.ltd.uk
Chain to Sheet Connection Detail
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Restraining Chain Connection Detail
There are 2 types of chains used, the top frame will use
shackle to hook type, while lower frames will use shackle
to shackle type.
Individual chain links selected to ensure all restraining
chains are evenly loaded.
5.3.3
Issue 2
MGF TECHNICAL FILE
WALERS AND STRUTS
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5.3.4
Issue 2
Type
Medium Duty Steel
Waler Lengths
2.0m, 2.5m & 3.0m
Material Grade
S275
Moment Capacity
12.7kNm
Section Modulus
69cm3
Type
Medium Duty Steel
Waler Lengths
3.5m & 4.0m
Material Grade
S275
Moment Capacity
19.3kNm
Section Modulus
105cm3
Type
Medium Duty Steel
Waler Lengths
5.0m
Material Grade
S275
Moment Capacity
31.4kNm
Section Modulus
171cm3
Tel. 01942 402 704
Heavy Duty Steel
Waler Lengths
3.0m - 5.0m
Material Grade
S460
Moment Capacity
40.5kNm
Section Modulus
132cm3
WALERS AND STRUTS
MGF TECHNICAL FILE
Type
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design@mgf.ltd.uk
Type
Medium Duty Aluminium
Waler Lengths
2.0m - 4.0m
Material Grade
6082T6
Moment Capacity
18.6kNm
Section Modulus
111cm3
5.3.5
Issue 2
MGF TECHNICAL FILE
WALERS AND STRUTS
Medium Duty Steel Waler
Medium Duty Steel Walers
Sheet to Sheet (mm)
Desc.
Waler
Weight (kg)
Code
L
(mm)
W
(mm)
C*MAX
(mm)
Min
Max
Assembled
Weight** (kg)
2000
70
1.120
2000
83
1420
565
3800
176
2500
88
1.125
2500
83
1920
565
3800
212
3000
97
1.130
3000
83
2420
565
3800
230
3500
112
1.135
3500
93
2920
565
3800
260
4000
129
1.240
4000
93
3420
565
3800
294
5000
180
1.250
5000
116
4370
565
3800
396
*
**
Depends of strut locations
Assembled weight includes 2 No. type 800 struts
Heavy Duty Steel Waler
Heavy Duty Steel Walers
Desc.
Waler
Weight (kg)
Code
L
(mm)
W
(mm)
C*MAX
(mm)
Min
Max
Assembled
Weight** (kg)
3000
100
1.330
3000
108
2420
565
3800
236
4000
133
1.340
4000
108
3420
565
3800
302
5000
166
1.350
5000
108
4420
565
3800
368
*
**
5.3.6
Issue 2
Sheet to Sheet (mm)
Depends of strut locations
Assembled weight includes 2 No. type 800 struts
Tel. 01942 402 704
WALERS AND STRUTS
MGF TECHNICAL FILE
Medium Duty Aluminium Waler
Medium Duty Aluminium Walers
Sheet to Sheet (mm)
Desc.
Waler
Weight (kg)
Code
L
(mm)
W
(mm)
C*MAX
(mm)
Min
Max
Assembled
Weight** (kg)
1500
18
1.015
1500
100
1010
565
3800
78
2000
24
1.020
2000
100
1510
565
3800
84
2500
30
1.025
2500
100
1910
565
3800
96
3000
36
1.030
3000
100
2410
565
3800
108
4000
47
1.040
4000
100
3310
565
3800
130
*
**
design@mgf.ltd.uk
Depends of strut locations
Assembled weight includes 2 No. type 800 struts
5.3.7
Issue 2
MGF TECHNICAL FILE
WALERS AND STRUTS
80kN Single Acting Hydraulic Ram Assembly
Hydraulic Cylinder
Single Acting
Material
Aluminium
Bore
50.8mm
Max .Working Pressure
400 Bar (6000 psi)
Test Pressure
400 Bar (6000 psi)
Approx. Working Stroke
800mm
Axial SWL
80kN
Min. FOS (by test)
2
Working Temp Range
-20ºC* to +50ºC
Approx. Pre-Load
20kN
Locating Pins
ĭ18 and ĭ20mm
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the full bore side of the piston
through the male QRV. Single
acting cylinders cannot be
retracted using a pump unit
and have to be physically
closed whilst releasing the
male QRV.
Ensure isolation valve is
closed to maintain pre-load
pressure and before release/
connection of QRV’s.
Pump Units
The pump is used to extend and retract the waler strut single
acting hydraulic rams.
The pumps contain bio-degradable Houghto Safe SF25
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diluted with water at a ratio of 3 parts water to 1 part Houghto
Safe SF25. In the Winter the mix ratio is 1:1.
Maximum recommended installation pressure 1500 psi (100
Bar).
5.3.8
Issue 2
Product ID
1.602 (SA)
Capacity
20 litres
Shoring Fluid
Houghto Safe SF25
Installation Pressure
0-1500 psi
Tel. 01942 402 704
WALERS AND STRUTS
MGF TECHNICAL FILE
The waler
hydraulic strut
is connected
to the waler
using a pin
and retaining
clip detail.
Waler Struts - Hydraulic
Single acting (SWL=80kN)
Ext. Dims.
Type
Code
Min
Max
Weight (kg)
600 (A)
1.455
550
900
13
800 (C)
1.480
800
1400
18
Min
Max
Weight (kg)
Ext.
1
1.525
250
N/A
5
2
1.550
500
N/A
10
3
1.510
1000
N/A
20
The waler strut
extension is
bolted to the
hydraulic strut
using 4 No. M10
grade 8.8 bolts
c/w nuts and
washers. The
strut extension is
connected to the
waler using a pin
and retaining clip
detail.
Extension bar
88.9 x 5.0 CHS
Grade S275
design@mgf.ltd.uk
5.3.9
Issue 2
MGF TECHNICAL FILE
WALERS AND STRUTS
5.3.10
Issue 2
SWL for Medium Duty Steel Walers at Various Strut Positions
Tel. 01942 402 704
WALERS AND STRUTS
MGF TECHNICAL FILE
SWL for Heavy Duty Steel Walers at Various Strut Positions
SWL for Aluminium Walers at Various Strut Positions
design@mgf.ltd.uk
5.3.11
Issue 2
MGF TECHNICAL FILE
WALERS AND STRUTS
Aluminium Vertishore
SWL = 20kN/m (on Vertishore)
*
5.3.12
Issue 2
Desc.
Product ID
Weight* (kg)
1500
1.014
28
2000
1.013
35
Assembled weight (excluding boards)
with type A struts
Pre-assembled, light weight, two sided hydraulic
waler strut system designed to be installed from
ground level directly against a soil face in the
vertical plane. Suitable for trenches up to 2.0m
deep and 1.4m wide. The System can be installed
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term utilities type trench work where the ground is
considered self supporting and capable of arching
a min. 1.5m between preloaded hydraulic vertical
supports for the duration of the works. Backing
boards are available to prevent localised pockets
of loose material entering the excavation.
Personnel should only enter and work in the space
between two vertishores.
A competent person should always inspect the
excavation before allowing access to ensure that
all the struts are pre-loaded and bearing directly
onto the soil, the exposed soil faces are self
supporting with no evidence of water ingress or
very loose material.
Vertical support must be provided at a max. 1.5m
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Always install and remove the system from ground
level and away from any potentially unstable
edges. Vertishores are supplied with an installation
kit, including a pump unit, lowering hook and valve
release tool.
Available hydraulic struts
Type A : 550-900mm
Type B: 700-1200mm
Type C: 800-1400mm
Tel. 01942 402 704
WALERS AND STRUTS
MGF TECHNICAL FILE
Waler End Protection Strut
MGF Endsafe Struts are
suitable for use in smaller
excavations when it is not
possible to safely batter the
ends of the trench back to
ground level.
The simple telescopic strut
system can be easily installed
and removed by one person
at the end of a waler run to
support trench sheets.
The pin connecting the inner
and outer sections should
always be used for safe
handling purposes and can be
removed once installed. The
minimum overlap between
the strut inner and outer is
Inner Material
90x90x4 SHS (S355)
Inner Unit Mass
10.5kg/m
Outer Material
100x100x4 SHS (S355)
Outer Unit Mass
11.9kg/m
Waler Hydraulic Strut and EndSafe Strut Connection Pin
design@mgf.ltd.uk
Pin
ĭPPEDUPP
long
Material Grade
080M40 (EN8)
Shear SWL
80kN
5.3.13
Issue 2
Safe Working Load for MGF End Protection Struts
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MGF TECHNICAL FILE
WALERS AND STRUTS
Safe Working Load for Waler End Protection Struts
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Recommended SWL
Arrows indicate recommended inner section lengths to achieve desired range.
5.3.14
Issue 2
Tel. 01942 402 704