Seismic Design of a Curved Steel Box Girder Bridge for the South Fraser Perimeter Road (SFPR)

The South Fraser Perimeter Road (SFPR) is a new 40km four-lane route along the Fraser River from the Highway 17 – Deltaport Way Interchange in Delta, to Highway 15 in Surrey. A new interchange connects the south end of the SFPR to Highway 17 and Deltaport Way. The major bridge structure in the interchange carries the SFPR over the CN Rail Right of Way and Deltaport Way eastbound ramp along a curved alignment at up to a 60° skew. The new 137m long, three span continuous bridge is comprised of three trapezoidal steel box girders with a composite concrete deck. Highway geometry and other site constraints limited the constructible sizes of pier columns and footings to an extent that they were not able to provide the necessary resistance to seismic induced lateral forces. In addition, soil conditions challenged the designers with potential for both settlement and seismic liquefaction potential. This paper presents details of the seismic analyses and design, and highlights the unique solutions. A seismic monitoring system was installed on the bridge that includes displacement transducers and accelerometers on abutments and piers paired with ones on the isolated bridge deck to capture the structural response to seismic events.

Hamersley, B., W. Wu and K. Mitchell. 2015. “Seismic Design of a Curved Steel Box Girder Bridge for the South Fraser Perimeter Road (SFPR),” Proceedings of the 11th Canadian Conference on Earthquake Engineering (11CCEE), Facing Seismic Risk, Victoria, British Columbia, July 24-24.