The SH25A bridge building team faced a challenging start to the week last week with the bad weather, but managed to continue placing the precast deck panels, drill soil nails to stabilise the slip face, and complete the earthworks at the eastern approach to the bridge, the transport agency says.
By last Sunday, 70 precast panels had been installed, Waka Kotahi NZ Transport agency said.
“As the panels are put in place they are ‘stitched’ together with steel reinforcement and concrete. Our steel fixers have already begun putting in the reinforcement, and the first of three concrete pours is scheduled for early this week.”
The first of two new drainage road crossings was completed and one of the 100T cranes was also demobilised as it is no longer required.
This week, weather permitting, the plan is to continue placing the precast deck panels and prepare for the deck stitch concrete pours.
“The team drilling for the soil nails made great progress on the slip face last week, working both day and night shifts.”
More about soil nailing
Soil nailing is a construction technique used to treat unstable soil slopes, such as the slip-face at SH25A Tarapahi. The technique involves drilling holes into the slope at a slight downwards angle and inserting reinforcing bars and grouting them into place. This helps tie the mass of soil together into a large stable block.
A flexible reinforcing mesh is usually then fixed in place over the top of these across the slope to help hold the shallow soils between the nails together.
Maintenance and recovery works
• SH25 Thames: Road resurfacing begins Sunday 12 November on SH25, south of the Goldfields shopping centre. The work will take place at night for two weeks, during this time stop/go traffic management will be in place, and from time-to-time side roads will be closed to help finish the work as quickly as possible. The affected side roads include Willoughby Street, Richmond Street and Sealey Street, access for residents will be provided from Pollen Street. Access to Richmond Street West will be maintained at all times.
• SH26 Puriri: Work to repair the road pavement began on Monday 6 November south of Kōpū, near Puriri. The work is expected to be completed within two weeks with stop/go traffic management.
• SH26 Murray Road: Asphalt resurfacing began on Sunday 5 November, and is expected to take one week to complete. Stop/go traffic management will be in place between 8pm and 5am each night. Minor delays are expected.
