Work at a rockfall site on the West Coast has reached an important milestone with the completion of a micropile retaining wall to improve resilience and safety for users of State Highway 6.
Efforts to reduce the ongoing rockfall risk have been underway at the Epitaph Rift site, north of Haast and south of Knights Point, since a storm in November last year triggered a slip. The event required an initial highway closure and ongoing traffic management since then.
Work at the site has included use of explosives and blasting to reduce and remove unstable pieces of rock above the road.
See an example of the rock clearing work at the Epitaph site.(external link)
In March, work shifted to the construction of the micropile retaining wall below road level, with funding of $1.7 million for the work.
“This has involved the construction of 110 metres of micropiles, down to depths of up to nine metres, to ensure the stability of the outside shoulder of the highway,” says Moira Whinham, Maintenance Contract Manager for NZTA on the West Coast.
“This wall is an important step to improving the short-term resilience of the site while work on a business case looking at long term resilience options is completed.”
Completion of the retaining wall means two lanes of unrestricted traffic are now restored on SH6.
“There is still some work remaining at the site to complete repairs to the road surface that was damaged during the rockfall and subsequent scaling that happened to make the site safe. This work needs to occur in warmer temperatures and is programmed for our next construction season this coming summer,” Miss Whinham says.
