7 Mile Dam
To improve the stability of Seven Mile Dam, BC Hydro contracted Con-Tech Systems Ltd. to supply 54 post-tensioned, corrosion protected, load-testable, restressable 92-strand anchors. The strand anchors were drilled through the concrete body of the dam, anchoring the dam to the underlying bedrock.
Each anchor consisted of 92 individual steel strands, with total lengths of up to 415 feet. Innovative techniques were required to meet BC Hydro’s specifications. As a result, Con-Tech Systems conducted extensive research to develop and design the anchors. To date, the strand anchors are the largest capacity anchors ever built in the post tensioning industry.
B.C. Hydro’s Seven Mile Dam is located on the Pend d’ Oreille River near Trail in southwestern British Columbia, approximately six miles upstream from its confluence with the Columbia River.
At a Glance
Project: Seven Mile Dam
Owner / Engineer: B.C. Hydro
Contractor: Peter Kiewit & Sons
Details: 57 tie down strand anchors: 92 strands, up to 415 ft long, wax encapsulated extruded strand, 2000 ton restressing system for future load monitoring