Effect of Dredging and Axial Load on a Berthing Structure

Abstract

Piles and a diaphragm wall of a supported berthing structure on marine soils are loaded both axially and laterally. Axial loads are typically generated by the self weight of the structure and external live loads; lateral loads are typically generated by wave current and seismic loads. These loads are generally considered in the design of berthing structures. However, the lateral force generated by lateral soil movements due to dredging may not be considered or accounted in the design of berthing structures. Hence, a full-scale field study was conducted on a berthing structure to estimate the actual axial load distribution during axial loading and the lateral displacement during dredging. After construction of the berth, it was decided to conduct a full scale axial load test on a single pile and monitor the lateral movements of the berth during and after dredging. This paper describes the load transfer data obtained from a bored cast – in – situ pile socketed 1.5 m into hard rock and the lateral displacement of the berth recorded during and after dredging to a -9.5 m dredge depth.