INNOVATION May-June 2019

VANCOUVER HOUSE The unique design of the 52-storey Vancouver House tower was specially adapted to allow for signi cant redevelopment of an area with limited buildable land while complying with setback requirements from the Granville Street Bridge. The tower, which starts o with a slender base, torques from its limited triangular footprint gently cantilevering as it ascends, allowing the tower to reclaim e ciency as it twists from a triangular shape into the optimum rectangular shape. Due to the increasing oor plates as it rises, the structure possesses a tendency to lean, which was counteracted by post-tensioning and o setting each oor plate by a calculated amount in the direction opposite to the lean. Vertical post-tensioning was used to compress one side of the building's core to counter the vertical tension created by the structure's lean, while the horizontal post-tensioning countered the tendency of the oors to twist as the structure leans with the construction of each new oor. Senior Engineer/Principal-in-Charge: Micheál O’Kee e, P.Eng.

SNOW AVALANCHE RISK ASSESSMENT AND HAZARD ZONING FOR STEWART, BC Stewart is located in northwestern BC, about 900 kilometres northwest of Vancouver. Stewart has a population of approximately 500, with municipal infrastructure that includes a school, recreation centre, hospital, airport, roads, and industrial port facilities. Given the history of avalanches in the region, including documented powder clouds impacting the town a er large avalanche events on slopes adjacent to the townsite, a determination of accurate avalanche hazard zones was required. The analysis completed was based on modern methods and included a review of avalanche occurrence records and historical accounts, aerial photo interpretation, detailed eld surveys, and extensive

numerical avalanche modelling. Avalanche runout estimates from each of these methods were combined using a con dence-based weighted average approach. Project Owner: District of Stewart. Participants: Alpine Solutions Avalanche Services: Brian Gould, P.Eng., Cam Campbell, Eng.L., Scott Thumlert, P.Eng. (APEGA)

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