PROJECTS

This headwall was constructed in the Tauranga Harbour. It was built behind a coffer dam, which kept three metres of ocean clear, with help from a six inch vacum pump.

The headwall was thirteen metres wide by four metres deep and three metres high.

The headwall was the outfall structure for the three DN1800 storm water pipes which drain the Mount Maunganui industrial area.

The structure was built with precast walls followed by a 600mm thick reinforced concrete floor. It required an undercut and of one metre deep to account for the soft marine sands.

The structure was mainly constructed of HD20 reinforcing steel and a 50MPa concrete with a 30% fly ash additive. The headwall was tied back to the existing ground using a special geogrid material.