The Still Creek Pedestrian Bridge located in the northwestern portion of Burnaby Lake Regional Park, forms an important connection within the park drawing over 300,000 visitors per year. Metro Vancouver retained Associated Engineering to provide engineering services for replacing the existing bridge with a prefabricated superstructure to improve freeboard and design capacity.
The project posed a number of challenges that included limited site access, poor ground conditions, highly compressible soils, and sensitive environmental habitat. We reviewed options for construction access and staging, including trail upgrades/ground improvements to support heavy equipment, installation with a heavy lift helicopter or accessing the site and installation using sectional barges. Helical piles with a cast-in-place pile cap was selected as the bridge foundation as the piles could be installed with relatively lightweight equipment with minimum impact and disturbance to the surrounding environment.
A prefabricated aluminum truss superstructure was selected to minimize overall weight and allow flexibility for the installation method chosen by the contractor. The successful contractor eventually selected to install the prefabricated bridge using a heavy lift helicopter. We provided services during construction that included environmental auditing of the contractor’s EMP, reviewing contractor submittals and daily construction inspection sheets to ensure compliance with the design and specifications.