The Brief
Wallace Building Contractors delivered specialist concrete construction works as part of the SH1 road widening project between Paremata and Plimmerton, including the construction of a 700-metre-long decorative retaining wall at Goat Point.
Constructed within the narrow corridor between State Highway 1 and the North Island Main Trunk railway line, the project presented significant logistical and engineering challenges. To safely and efficiently construct the wall within the restricted working space, Wallace designed and manufactured a custom rolling formwork system incorporating a purpose-built steel mould, mobile gantry, and winch-operated lifting system. The innovative methodology enabled the decorative wall pattern to be maintained consistently while accommodating changing wall heights along the route.
In some locations the works were undertaken just 1.5 metres from active rail infrastructure and within 100 millimetres of the North Island's main fibre optic cable. Additional project elements included wall foundations, galvanised pedestrian barriers, streetlight foundations, and cast-in sockets for lighting infrastructure.