INNOVATION May-June 2017

Condition of overpass inspected within arm’s-length distance

of specialized in-house bridge inspectors who included both qualified rope access technicians and professional engineers, the inspection was completed within arm’s-length distance. The use of rope climbers and efficient traffic management plans reduced public inconvenience typically caused when roadways are closed for traditional bridge inspection. APEGBC members, Stantec: Mekdam Nima, P.Eng., Kip Skabar, P.Eng., Niall Eivers, EIT, Frances Wee, EIT, Yuki Kishimoto, EIT pier shapes, sizes and locations; scour-protection options; ship-impact protection; construction and demolition techniques; and mitigation for off-site scour or sedimentation impacts. Tests using the model incorporate known flow scenarios, as well as potential impacts from climate change and sea- level rise. Testing is supplemented by geomorphic analysis, current-velocity measurements, and numerical modelling. APEGBC members: Kara Hurtig, P.Eng., Matt Gellis, P.Eng., Jeff Van Tol, EIT, Ken Curry, P.Eng., Gord Ruffo, P.Eng., Sany Zein, P.Eng., Phoebe Cheung, P.Eng.

The seven-year-old Coast Meridian Overpass is a six-span, 580-metre, cable-stayed bridge over the Canadian Pacific railyard in Port Coquitlam. The landmark serves as a critical connection along TransLink’s regional major roads network. To optimize the bridge’s long-term performance, Stantec completed a detailed condition inspection and multi-year maintenance program for the overpass. The inspection’s purpose was to verify the condition of the overpass’s structural components and identify defects that could affect public safety and bridge performance. With the help Northwest Hydraulic Consultants Ltd. (NHC) was retained by TransLink and Parsons to undertake hydrotechnical testing and design for Translink’s Pattullo Bridge Replacement Project. Because of the complex hydraulics and sediment transport dynamics at this Fraser River- crossing location, and the proximity to the New Westminster Rail and SkyTrain bridges, NHC is conducting a 1:80 mobile-bed physical model study to assess feasibility and design mitigation for near-field instream impacts. The model will test hydraulic and morphologic impacts of the project’s reference concept, and develop specifications for the design–build phase of the project. Specifications could include The Cheakamus River Pedestrian Bridges project comprises construction of two new pedestrian suspension bridges over the Cheakamus River, linking key recreational trail segments near Whistler, BC. The bridges are the Sea to Sky Bridge and the Train Wreck Bridge. The Sea to Sky Bridge incorporates an asymmetrical design with different-height towers that are inclined backwards to allow for a steeper backstay angle. This prevents the bridge cables from encroaching on an existing forestry road.

Assessing risks and options for Pattullo Bridge

Suspension bridges built on the Sea to Sky Trail

The Train Wreck Bridge provides safe, legal access to an old train wreck site —a popular landmark visited by both locals and tourists. Anchor frames for the cables at each end of the Train Wreck Bridge are designed in the form of locomotive wheels as an interesting and appealing tribute to the wreck site. Klohn Crippen Berger Ltd. provided conceptual- and detailed-design and construction-management services for both bridges.

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