The new main water supply is constructed in a tunnel driven through soil, deep underneath the riverbed. It crosses between Maquabeak Park in Coquitlam on the north side of the river, and Surrey on the south side of the river.
The project’s 3.5m (11.5ft) o.d. Caterpillar EPBM successfully completed the crossing on Thursday June 25, reaching the shaft on the North Shore of the Fraser River.
The 1000m long tunnel is the first TBM tunnelled crossing of the Fraser River, and with EPB pressures of up to 6 bar, was one of the highest EPB pressure tunnels seen to date in North America.
Project owner, Metro Vancouver, awarded a CA$150 million contract in March 2011 to MAJV, a joint venture between McNally Construction and Aecon Constructors, a Division of Aecon Group.
Designed to replace an existing subaqueous watermain crossing, and provide an earthquake resistant water supply for communities south of the Fraser River, the project will improve system reliability and help ensure the continued delivery of high-quality drinking water to growing communities south of the Fraser River.
The completion of the tunnel allows work to commence on the installation of the 2.1m (6.8ft) diameter welded steel carrier pipe within the tunnel, which will be grouted into place.