Results
Failed ridge line stabilised with anchored mesh system.
Safer conditions restored for SH1 tunnels and road users.
Program efficiencies achieved through adaptable drilling and grouting methods.
Highway successfully reopened following post-earthquake geohazard mitigation.
Project
Solution
Installation of 4,000m² of TECCO G65/3 active mesh system.
Nearly 1,000 hollow and solid bar anchors drilled to 6–9m depths.
Modified grouting method using ‘gentler’ grout flush to reduce soil disturbance.
Pumping systems set up for grout delivery up to 80m above road.
Use of high-reach drills and crane-supported equipment to improve production.
Lightweight wagon drills deployed for higher slope areas with limited access.
Project
Challenges
Slope failure above SH1 tunnels with repeated high-energy rockfalls.
Razorback ridge over 100m long, only metres wide in sections, prone to collapse.
Collapse of the crest during initial anchor installation.
Restricted access for equipment on steep slopes and above tunnels.
Program-critical delivery under challenging post-earthquake conditions.
Project
Overview
Following the 2016 Kaikōura Earthquake, SH1 and several tunnels south of Kaikōura were closed due to major slope failure and repeated rockfalls.
The unstable ridge line above the tunnels required 4,000m² of Geobrugg TECCO mesh, anchored to both soil and rock, to stabilise the failed slopes. Innovative drilling and grouting methods were adopted to safely deliver anchors on difficult terrain up to 80m above the road, allowing the highway to be reopened with reduced risk.