The Fraser Heights Wetlands Viaduct is an integral component of the new South Fraser Perimeter Road and Port Mann Highway 1 projects which connect Deltaport to the Golden Ears Bridge and Highway 1 corridor.

GIG completed this very unique design-build segment of the overall Port Mann Highway 1 Project. This $17 million bridge consists of two 500m long separated parallel structures crossing a very environmentally sensitive wetland eco-system. Heavy equipment was not permitted in the bridge right of way or surrounding wetlands area; therefore some innovative solutions had to be found in order to build the structures.

This project was built using a “top down” construction method; meaning that the structure itself was used to support construction loads with no heavy equipment on the ground. The original design of the bridge accounted for these extremely large loads which meant that the structure was significantly overdesigned for the final service design loads imposed on it.  During the design optimization phase of the project, GIG developed a construction methodology solution which would remove construction loads from the permanent structure thus streamlining the design and reducing construction costs significantly.

The work involved driving 610mm diameter pipe piles to depths in excess of 30m, filling the piles with concrete and reinforcing steel, installing prefabricated structural steel pile caps and girders and placing of precast concrete deck panels for the finished roadway. Work on both parallel structures was carried out from the North structure only. The work also included construction of abutments and end fills incorporating MSE retaining walls. Due to the environmental red zone classification of the site, all clearing activities were done by hand work using small tools and light equipment only. A detailed Quality Management Plan, which had to align with the very strict overall Quality Plan for PMH1 Project, was implemented on the project.