FSG was engaged in 2013 to assist Opus and the Port of Lyttelton in resolving technical issues associated with the remediation of Cashin Quay at Lyttelton which serves as the port of Christchurch, New Zealand. The Port is located on the edge of what was once a volcanic crater, and the challenging ground conditions consist of a significant depth of fill material, overlying soft marine sediments, volcanic sediments, and residual rock, which overly a steeply sloping volcanic bed-rock.
Around 250 No. driven steel tubes were initially required as foundation piles for the new wharf at Cashin Quay, Berth 2 (CQ2), which is the first stage of the works. Recognising the complexity of the ground conditions and the need for well-considered design, thorough constructability planning, and sound verification processes, Opus sought end-to-end project involvement from FSG.
FSG services in the preconstruction phase included back-analysis of previous dynamic and static load testing of existing piles, and design and driveability analysis of new tubular steel piles. Expected founding levels were at depths of around 50m to 70m. FSG provided constructability advice in relation to hammer selection, installation and verification procedures for the very long slender piles, input to piling specifications, risk management and pile procurement advice, and review of tender proposals and construction methodologies
The project delivery phase commenced in early 2014 and FSG has been engaged to provide PDA and PDM testing services, and engineering sign-off for all piles. A streamlined and efficient verification process has been developed and implemented by FSG to ensure pile sign-off in a timely manner, which is critical to the progress of the works. The works are progressing well, and piling is around 50% complete at the time this newsletter was written.