Herne Bay Connector Trunk Sewer Upgrade
An extension to the NZD1.2 billion super-sized Wastewater tunnel across central Auckland to enable future expansion and growth of Auckland, to become New Zealand’s largest bored waste water tunnel.
RDCL was engaged to undertake at MASW survey of the Herne Bay connector alignment to understand the variations in the East Coast Bays Formation (ECBF) between the boreholes that were drilled at 200 – 300 meters spacing.
This process was used to reduce the uncertainty in ground conditions and to assist in the development of a 3D ground model.
RDCL was able to deploy a rapid screening seismic (MASW) array along the whole proposed alignment (circa 2 km) over a period of 2 days.
Using multiple soundings at 10 m intervals, RDCL was able to create a 2D cross-section down to a depth of 24 m along the alignment. The data collected, together with downhole data also acquired by RDCL, was used for seismic strength calculations by the Herne Bay design team.
Wireline Geophysics, Surface Geophysics, MASW
