Geohazard Engineering
Lone Kauri & Karekare Roads
8 slip sites, West Auckland — 2,647 m soil nails, 881 m² shotcrete. Cyclone Gabrielle repair.
- Location
- Karekare & Lone Kauri Road, West Auckland
- Customer
- Fulton Hogan / Auckland Transport
- Designer
- Andy O'Sullivan
- Timeline
- October 2023 — January 2025
- Scope
- Soil nails, shotcrete, permeable concrete build-out
Design
Eight Sites, One Integrated Programme
Cyclone Gabrielle in February 2023 caused widespread slope failures across West Auckland's road network. Lone Kauri and Karekare Roads — critical access routes into the WaitÄkere Ranges — suffered eight separate slip sites requiring immediate remediation to restore full two-way access for residents and emergency services.
GSI was engaged by Fulton Hogan and Auckland Transport to design and construct the repairs across all eight sites under a single integrated programme. Working with Andy O'Sullivan Geotechnical Engineering, GSI delivered designed solutions for each site involving the installation of spider anchors, rock bolts, soil nails, and flexible mesh — matched to the geology and failure mechanism at each location.
Build
2,647 Lineal Metres of Soil Nails
Works were sequenced across all eight sites simultaneously, with GSI crews cycling between locations to maintain programme momentum. Across the full programme, 2,647 lineal metres of soil nails were installed, 881 m² of shotcrete facing applied, and 372 m² of flexible mesh facing placed. Drainage upgrades, guardrail installation, and full road reinstatement were completed at each site. The tight access constraints of the narrow road corridor through the WaitÄkere Ranges required continuous traffic management and careful sequencing to maintain resident access throughout construction.
Deliver
Critical Access Restored to the WaitÄkere Ranges
All eight slip sites were successfully stabilised and reinstated within the programme period, restoring full two-way vehicle access on both Lone Kauri and Karekare Roads. The works were completed to Auckland Transport's specifications and client satisfaction — delivering a streamlined, cost-effective solution for the repairs.
The project further cemented GSI's position as the go-to design-and-build geohazard contractor for Fulton Hogan and Auckland Transport — demonstrating the efficiency of managing multi-site remediation programmes under a single integrated contract.
The Lone Kauri and Karekare programme stands as one of the most comprehensive multi-site slip repair projects completed in the Auckland region following Cyclone Gabrielle — demonstrating the capacity to manage a high-volume repair programme efficiently under a single design-and-build contract.
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Problem
Slope Instability →Related Projects
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