In New Zealand, C3 contract foundations works have well progressed and the learning curve is far behing. This ultra-urban project, in Auckland Centrtal Business District, is divided into three geographical areas, as part of the project’s newly created stations. These works mainly consist of diaphragm walls, bored piles, plunge columns and anchors whose numerous interfaces with the public and the existing structures make it a worksite with site specific technical and logistical challenges recalling of the Asian megalopolises.
Following the site preparation initiated in September 2019, the first piles were completed in February 2020 at the Mt Eden station. The Covid-19 crisis suddenly put the on-going activities on hold and further delayed the start of the rest of the works. Once the end of the lockdown period, imposed by the New Zealand government, went to an end in late April 2020, the Mt Eden piling works resumed, followed gradually by Aotea station Piles in early June 2020, and the Aotea and K-Road diaphragm walls in July 2020.
Diaphragm wall works at the Aotea station
Diaphragm wall work at Beresford Square station (K-Road)
All preparation and production activities were made possible by pooling together the personnel and equipment resources of SBI GP and March Construction Ltd (a local Soletanche Bachy subsidiary in New Zealand). The flawless support from the the SBI export team allowed the two DWall set shipments from France to arrive at Auckland Port on time (each workshop comprising an HC05, a KL mounted on LBH8100, a Sotres 500 and a Sotres 120) as well as two pile workshops (LB28 and SR40).
Amongst the usual daily site challenges, some aspects are worth noting. In addition to the logistical challenges experienced by all overseas projects throughout 2020 (supply chain of equipment and qualified personnel), the solution developed for removing redundant anchors under tension through the Aotea Dwall alignment was particularly noteworthy. Specific cutting discs have been designed, manufactured and fitted to the drums of the HC05. The first results were proved satisfactory and have confirmed the method to cut out the remaining 30 anchors, at approximately 8m deep.
The 24,000 sq. m of Dwall, representing circa 200 panels, and the 750 nos. of bored piles, representing 14,000 linear metres, will be progressively completed over the course of 2021, with the work currently scheduled to end in early November 2021. A demobilisation phase will follow, during which the teams will withdraw from the project by the end of the year.
A multi-skilled general contracting project for Soletanche Bachy International
As part of the City Rail Link project in Auckland, Soletanche Bachy International is part of the Link Alliance consortium, alongside VINCI Construction Grands Projets (lead company), plus designers Aecom, WSP-Opus and Tonkin & Taylor.
The consortium partners are involved in equal proportions in the implementation of packages C1, C3, C5 and C7 of the City Rail Link project, carried out as general contractor and covering all the works (design-build, civil engineering, foundations, electrical systems, signalling, etc.). This is a good opportunity for Soletanche Bachy International to make the most of its ability to carry out multi-operations project!
Alongside the client City Rail Link Limited, the Link Alliance consortium will be responsible for delivering all lots 3, 5 and 7 in 2024. As a reminder, the last acquisition back to October 2020, with:
- Package 5: construction of two structures (grade-separated junctions) and 2 km of new track, to be constructed while maintaining traffic on the North Auckland Line.
- Package 7: installation of power supply, overhead lines, signalling and the control system for the entire City Rail Link.