Construct a sheet pile coffer dam to enable a concrete outfall structure, designed to accommodate three DN1800 stormwater pipes, to be built.
The sheet pile coffer dam was built out into Tauranga Harbour and was used to keep around three metres of water out at high tide.
The sheet pile coffer dam was seven metres by fifteen metres and was constructed with eight metre clutched interlocking sheets. The coffer dam was sealed water tight with hemp rope.
The pit was dewatered using a six inch vacuum pump and a sump arrangement. It was constructed to enable a concrete outfall structure to be built. The outfall structure was designed to accommodate three DN1800 stormwater pipes.
The sheets were driven in using a 35 tonne excavator and a Movax sheet piler.