The Port Botany Expansion Project is a major expansion of the existing container terminal and port on the north east corner of Botany Bay, Sydney.
The expansion will provide five new berths for large container ships as well as tug berths, and major civil and road works and 65ha of reclamation for hardstand container storage. A major component of the project is a 1.85km of concrete quay wall constructed from 215 precast counterfort retaining wall units.
This paper focuses on the design methodolies to design the 20m high x 15m long x 9m wide concrete counterfort unit.
The counterfort units have been designed to support crane, lateral earth, berthing and mooring loads. The design lateral earth pressures were determined by an innovative process using a geotechnical 2D soil modelling software and a 2D structural modelling software. The initial lateral earth pressures were determined using the soil model and applied to the structural model, deflections of the soil and structural models were compared and the stiffness of the wall within the soil model revised. The revised lateral earth pressures from the soil model were fed back into the structural model, the process was continued until deflection conformity was reached between the two model
The end product from the process was a lateral soil pressure profile that was used to refine the structural design of the counterforts and used as upper bound pressure profile during the vibro-compaction of the reclaimed sands to ensure the design capacity of the counterfort was not exceeded.