Results
Rockfall attenuator constructed safely in a high-risk earthquake slip zone.
SH1 successfully reopened with reduced rockfall risk to road users.
Construction delivered to program despite challenging conditions.
Long-term resilience provided for a critical national transport corridor.
Project
Solution
Sluicing and scaling to clear loose debris from the slip face.
Helicopter-assisted meshing of the head scarp to allow safe team access.
Crane-supported drilling from lower-risk zones to construct foundations.
Installation of a 120m long, 4m high 2000kJ rockfall attenuator with 30m drape.
Safety-first methodology ensuring controlled construction despite extreme terrain.
Project
Challenges
Large slip above SH1 with head scarp 200–250m high and unstable boulders.
Hazardous, unconsolidated soils and newly exposed rock in a high-risk zone.
Requirement to deliver works quickly to meet road reopening dates.
Restricted access for plant and drilling equipment.
Project
Overview
A major slip triggered by the 2016 Kaikōura Earthquake closed SH1 south of Kaikōura, with debris funnelling through a 90m-wide chute towards the highway. After extensive sluicing and scaling, a 2000kJ rockfall attenuator system was designed and constructed 30m above the road on newly exposed bedrock.
The works combined helicopter meshing of the head scarp, crane-supported drilling, and controlled construction methods to deliver a 120m long, 4m high attenuator with a 30m drape, ensuring highway protection and safe reopening.