Slope Rehabilitation and Berth Deepening of Port

Berth Nos. 2, 3 and 4 at Fraser Surrey Docks are used for loading and unloading of break bulk cargo from deep sea vessels. Constructed in the late 1960's, the three berths are continuous with a total wharf length of 550 m. The berths are of similar construction and consist of a tied-back steel sheet pile bulkhead wall with a concrete pile, pile cap and deck structure forming the berth face in front of the bulkhead. An inspection of the facility in 2008 indicated that the soil elevation in front of the sheet pile wall was significantly lower than the original design elevation with factors of safety against failure that were below acceptable level. Rehabilitation of the slope protection was necessary to reinstate the facility to an operational condition. In addition to the rehabilitation work, the dredge depth was to be increased in order to accommodate vessels of increased dimensions and reduce the dependence of berthing on tidal variations. To achieve the desired additional berth depth and reinstatement of the wharf's design capacity, a sheet pile pony wall constructed along the existing face of the dock in combination with reinstatement of the fill in front of the sheet pile bulkhead wall was selected as the preferred option. The project presented some unique challenges due to the geometry constraints presented by the existing deck structure. This paper will present the details of the design, review the challenges associated with construction and present the approaches taken to complete this unique rehabilitation project.