Source: New Zealand Transport Agency
Work is due to get underway this week on providing longer term protection from slips on State Highway 7 near Lewis Pass.
A high tensile steel mesh will be anchored to the headscarp/crest of the slope at the slip site near Riordons Creek, between Hanmer Springs and Springs Junction. A slip at the site in June reduced the highway down to one lane with traffic signals and a 30km/h speed restriction and required a series of overnight closures while clearance work was carried out.
The latest measures are aimed at preventing future slips and risks to motorists, as well as further disruption to travel through the area.
“The mesh will be pinned over the crest of the slope to help prevent it from failing or regressing,” says NZTA system manager Mark Pinner.
“We are also including an erosion matting behind the mesh to help hold the weak soil layer at the top of the slope in place and enable vegetation cover to re-establish.”
The work is due to begin tomorrow (Wednesday 27 August), when crews will mobilise on site and do some anchor testing through until Friday 29 August. This will mean that the site is reduced to one lane with temporary traffic signals from 7am to 7pm. Two lanes will be open overnight.
After a period offsite, to analyse the test results and refine the design, crews will then return on Tuesday 9 September for installation and supporting work that is due to be complete by Monday 6 October. Further traffic management will be in place at this time.
We thank road users for their patience while this work is carried out. People can stay up to date on the status of this and other highways at our Journey Planner site(external link).
An example of anchored steel mesh to prevent rockfall/slips, in Kaikōura.
An image from the Riordons Creek slip site in July.
