Teck Highland Valley Copper Partnership built a multiplate overpass northeast of their Highland Mill Facilities, 16 km west of Logan Lake, British Columbia. The multiplate overpass provides grade separation between Moran Place that is the main access to the HVC Mill from Highway 97C and a new haul road that crosses over Moran Place and allows traffic of loaded Cat 797B mining trucks from the main pit to the new rock dump facility northeast of the Mill. The multiplate arch has a 15 m-span, a 6.6 m maximum clearance and is 58 m-long.
Klohn Crippen Berger (KCB) conducted a geotechnical investigation for the foundation design. The multiplate was founded on two strip footings, each 65 m-long and 5.5 m-wide. The footings were designed to be founded at a depth of 1.3 m below the road surface grade.
KCB provided quality assurance testing for the backfilling of the foundation fill, and for the multiplate structure’s critical backfill zone.
The construction of the multiplate structure took place from September to December 2009. Due to fill placement and compaction occurring during freezing weather, it was necessary to take special precautions during construction, including adding geotextile reinforcement at each 200 mm lift for the structure backfill, and maintaining the backfill moisture content well below the optimum moisture content.
- Geotechnical investigation
- Construction monitoring