The project involves the design and construction of a 4.6km long seawall east of the existing reclaimed areas at the Port of Brisbane. The construction of the seawall is the first step in allowing the Port of Brisbane Corporation (PBC) to reclaim an additional 230ha for the future expansion of the Port. The design and construction was carried out as an Alliance between the client (PBC) and a team consisting of Coffey Geosciences (Geotechnical Consultant), Leighton Contractors (Contractor), Parsons Brinckerhoff Australia (Civil Consultant) and WBM Oceanics (Hydraulic Consultant).

Significant geotechnical, environmental and construction constraints were associated with the project because of the subsurface profiles, close proximity of the Moreton Bay Marine Park, varying water depths and expected sea conditions during construction. Soft clays are encountered along the full length of the alignment with the thickness varying from 6m near the existing reclamation increasing to 30m towards the east. The consistency of the soft clay at the seabed surface is very soft to soft, with undrained shear strengths as low as 5 kPa. This paper concentrates on the design and construction of the eastern portion of the seawall.