Source: New Zealand Transport Agency
Contractors will be on the ground on Monday to begin repairs on an underslip on State Highway 60 Tākaka Hill.
Drone shot of underslip site, SH60 Tākaka Hill.
The slip, uphill from the Riwaka Valley Road intersection, happened during wet weather in late June. The road has been restricted to one lane and stop/go traffic management while planning for repairs has been underway.
Rob Service, System Manager Top of the South, says work crews will start work on the slip next Monday (26 August).
“They’ll start with drainage works uphill from the slip before a new retaining wall is built. Keeping water away from the site is essential to prevent more slips in the future.”
Mr Service says the repair is a substantial job, requiring heavy equipment and vehicles on site.
“We’ll be using around 30 steel posts, each 12 metres long, timber lagging, and anchor bars to stabilise and reinforce the slope. There will also be drains behind the new reinforcing wall to control sub-surface water.”
“The road will also be resurfaced once the slip is repaired. The aim is to get all this complete and the road back to two lanes before Christmas,” Mr Service says.
The road will remain restricted to one lane under stop/go traffic management while the repairs are completed.
Mr Service says it means drivers can still expect short delays while travelling over the hill.
“Where possible, we will work with other maintenance planned for the Tākaka Hill to ensure the job is completed as quickly and efficiently as possible. We will make sure the community is kept informed so they can plan their travel effectively.”
“Fixing this slip is a priority for us. We know the Tākaka Hill is a critical transport connection,” Mr Service says.
SH60 underslip repairs – facts and figures
- Contractors are using a similar approach to other underslip repairs on the route.
- 26 to 30 twelve metre steel posts will be used with timber lagging. Each post will be driven into the soil to 75% of its length and they spaced approximately one metre apart.
- Anchor bars will be used instead of rock anchors because of poor soils at the site.
- New drainage will be installed – uphill from the slip site and subsurface behind the new retaining wall.
- The road will be resurfaced once repairs are completed.
