CH-RWSR-CA-Endako Mine Retaining Wall,British

CASE HISTORY
Rev:00, Issue Date 07.22.2014
ENDAKO MINE RETAINING WALL
Fraser Lake, British Columbia, CANADA
Mechanically Stabilized Earth Wall
Products: Terrawall, MacGrid WG30
Project Background:
The Endako Mine is an open pit molybdenum mine located
near Fraser Lake, 160km northwest of Prince George, British
Columbia. During an expansion in 2008, an in-pit crusher was
relocated, requiring the construction of a large retaining wall.
The Endako Mine is a fully integrated facility that began
operations in 1965. It includes a concentrator that process ore
through crushing, grinding, and floatation circuits
Problem:
The proposed retaining wall had an irregular layout as it was
necessary to use the retaining wall to create a dump pocket
around the in-pit crusher. At the highest point, the wall had to
be approximately 13m high, with a length of 92m. Ore trucks
hauling to the crusher required that the wall be designed to
support loads of up to 150kPa. The engineering consultant
retained by Endako Mines to implement the expansion of the
mine, Tetra Tech (formerly Wardrop Engineering), approached
Maccaferri Canada Ltd. to discuss the feasibility of the
proposed retaining wall.
View of finished Terrawall system
Solution:
Using information provided by Tetra Tech, Maccaferri technical
staff designed the mechanically stabilized earth wall using
Terrawall woven wire mesh facing units and high strength
MacGrid WG geosynthetic reinforcement.
GeoNorth
Engineering Ltd. was retained by Maccaferri to conduct the
final review of the design and to provide periodic inspection
services of the engineered backfill.
The height of the structure and the loading imposed by the ore
trucks necessitated the use of high strength geosynthetic
reinforcement. Using 65cm high Terrawall units, MacGrid
WG30 (Tult=300kN/m) was selected as a suitable
reinforcements. The length of reinforcement was up to 15m
long in some locations within the structure.
Once completed, the MSE wall had a frontal face area of
approximately 1,280m2.
Terrawall is a structure made of the double twisted hexagonal
woven heavily galvanized and PVC coated wire mesh that are
used for soil retaining applications. The TerrawallTM units are
supplied already cut to the specified measurements without
requiring cutting on site. The can be used as soil retaining
structures or as facing units used in conjunction with high
strength polyester geogrids (MacGrid WG, ParaGrid or
ParaLink)
Owner/Operator:
Thompson Creek Endako Mine
Products used:
Terrawall, MacGrid WG30
Date of operation
October/November 2008
Support Loads 150kPa CATERPILLAR 789C Haul Truck
MacGrid® WG series geogrids are used predominately in
Mechanically Stabilized Earth (MSE) and Reinforced Soil Slope
(RSS) structures as soil reinforcement. MacGrid® WG geogrids
are made from high molecular weight, high tenacity polyester
multifilament yarns. The yarns are woven under tension in the
machine direction and finished with a polymeric coating.
MacGrid® is engineered to be mechanically and chemically
durable, and resistant to biological degradation.
View of the Haul Truck dumping on dump pocket
Closer view of Terralwall System
Closer view of the opposite side of Terralwall System
Plan and Elevation View
Cross Section
400 Collier MacMillan Drive, Unit B
Cambridge, ON N1R 7H7
Tel: 519-623-9990
Fax: 519-623-1309
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