New Zealand Pressure Jacking Pipe Project Successfully Passes 10 Bar Pressure Test

Global Pipe have achieved a significant industry first with a successful pressure test of 10 Bar for the Wairua Road Rising Main project. A first for a one-pass pressure trenchless solution in New Zealand.

The project was originally designed using a HDPE pressure pipe. Global Pipe assisted March Cato and Opus by converting the project design to use HOBAS CC-GRP Pressure Jacking Pipe. This resulted in significant financial savings for New Zealand ratepayers and Watercare NZ. HOBAS’s Pressure Jacking Pipe provided a one-pass trenchless solution under the busy Wairua Road minimising disruption to local traffic and the community.

Project Planning and Engineering:

• Global Pipe worked with March Cato and Opus to design and specify HOBAS CC-GRP Pressure Jacking pipe, including:
  • Specification of CC-GRP Jacking Pipe
  • Pipe stiffness calculations
  • Project jacking loads
  • Joint deflection
  • Project cost and savings calculations
  • Design of GRP fittings and flange connections
  • Design of thrust blocks
  • Global Pipe’s Engineering team trained March Cato how to handle and install HOBAS CC-GRP Pressure Jacking Pipe
  • Seamless delivery of pipe to the project site with Global Pipe’s logistic and storage solution.

HOBAS’s CC-GRP Pressure Jacking Pipe will provide the Wairua Road community a reliable and secure sewer connection for the next 100 plus years.

Project Owner: Watercare NZ
Project Head Contractor: March Cato Civil Engineering Contractors
Project: Supply of 682m OD 1099 HOBAS CC-GRP PN10 Pressure Jacking Pipe

The Wairau Pump Station located in the Wairau Valley, north of Auckland is located in challenging terrain in the middle of a commercial and industrial area. Microtunnelling at a depth of 5.5m was required under one of Auckland’s regional arterials which carries approximately 12,000 commuters a day. The new sewer main replaces an existing wastewater rising main installed in the 1960s and is part of an Auckland wide upgrade of wastewater infrastructure by Watercare.

This project was originally planned to take place in 2014 using HDPE and directional drilling as the main form of installation. March Cato and Watercare realised this methodology and pipe material choice on a busy road just off the Northern Motorway would be problematic. March Cato sourced an alternative construction option to better suit the project – the new proposed method would be to use HOBAS CC-GRP Pressure Jacking Pipe supplied by Global Pipe and a Herrenkneckt Tunnel Boring Machine. In doing this, launch shaft and receiving pits could be isolated to areas where there would be no need to shut down road access for cars.

Global Pipe provided full technical support and supply of all Hobas pipe during the project. This was the first time HOBAS CC-GRP Pressure Jacking Pipe was used in New Zealand. This enabled Watercare to deliver a solution for the problems faced at Wairua Road Rising main with significantly less disruption during construction.

Read more about this project here.