Results
All three slip sites stabilised with an integrated system, delivered within the contract period despite scope increases.
Positive client outcome and strengthened team capability (training, leadership, H&S culture) recorded as project highlights.
Approach validated for complex urban slopes with live-traffic interfaces.
Project
Solution
Pivoted from the IFC-specified 150mm anchors to grout-flush hollow bar after bespoke wagon-drill trials proved unworkable in collapsing ground.
Deployed dimensioned systems matched to slope zones: TECCO and GREENAX active meshes, two DELTAX drapes, a 4m attenuator, and four catch fences.
Maintained programme and safety through staged access, extensive scaling, and traffic management.
Project
Challenges
Extremely poor ground (bottomless voids, collapsing holes) required months of method trials before a stable anchor approach was established.
Difficult access, active slips and weather/COVID impacts; two months of scaling and temporary drapes were needed to make areas safe.
Continuous public interface with 24/7 live traffic running below the works.
Project
Overview
Following heavy rainfall, two large slips - followed by a third during works - developed on the steep, seismically active slopes of Ngaio Gorge. The main slip and lower slip sat above live traffic and in notoriously difficult ground with collapsible soils, voids and rockfall exposure. The brief required a multi-system design and staged delivery to stabilise the slopes, maintain public safety and manage interfaces on a highly visible urban site.