The assignment was for a condition inspection and the seismic retrofit and rehabilitation assessment. The Knight Street Bridge crosses the two branches of the north arm of the Fraser River. The north structure consists of seven spans and the south structure has thirty spans. Each structure has a three span concrete box girder river crossing with simply supported prestressed girder approach spans. A full condition inspection was carried out with a peeper truck used on the main river spans. Separate seismic assessments were carried out for the north and south structures. For each structure global models were prepared and spectral analysis carried out. At selected bends, non-linear pushover analyses were carried out in the transverse direction. Due to the considerable length of the south structure, a time history computer analyses was also carried out. Computer models were also used to investigate predicted liquefaction displacements. Conceptual retrofitting designs and cost estimates were prepared and submitted to the Ministry.

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