Waiari Trunk Main Construction

NZ
HEB Construction
2020

Abergeldie completed the Waiari Trunk Main Construction in collaboration with HEB Construction, who were working on behalf of Tauranga City Council to install casings under the railway embankments.

The project was located in Te Puke, a town in New Zealand's Bay of Plenty region, and formed part of Tauranga City Council's investment in the Waiari Water Supply Scheme, the city's third water treatment facility.

This new plant has provided a clean water supply for around 35,000 family homes, meeting Tauranga's future needs and providing backup for the Western Bay of Plenty District Council.

35,000

HOMES PROVIDED WITH CLEAN WATER

15m

SHAFT DEPTH

2

STEEL CASING PIPES INSTALLED

43m

CASING PIPES EXTENDED REACH

Scope of works

The scope of work included: 

Abergeldie’s scope of works included the installation of two casings under rail embankments, with each drive installing a 1000mm ID x 20mm wall thickness casing over a distance of 43m, launched from a 15m long shaft.

Trenchless casing installation of two steel casings under KiwiRail ECMT rail line including:

  • Excavate sheet piled launch shaft.
  • Temporary works structure installations.
  • Installation of concrete floor and pipe hammering equipment.
  • Installation of two 1000mm ID steel casing pipes via pipe hammer methodology.

Complexity

Working underneath KiwiRail assets, Abergeldie utilised the approved and preferred Pipe Ramming Method, which has very low opportunity for settlement. In this method, the Grundo Ram Taurus Hammer progresses forward while retaining the spoil entering the casing, creating substantial face pressure with the assistance of an inflated plug installed at the launch shaft. The Pipe Ramming Method is effective, even through poor soil.

The hammer produces 18600N of impact, propelling the casing forward at up to 200mm per minute.

The team reached a major milestone in late June 2020 when they entered the final stages of the project, despite major delays due to COVID-19 Level 4 Lockdown across New Zealand.

Community benefit

This new plant ensures a clean water supply for around 35,000 family homes, to meet the future needs of Tauranga and provide back up for the Western Bay of Plenty District Council.