A major milestone was reached last week in the upgrading of the Raglan Deviation section of State Highway 23, approximately 20km west of Hamilton.
The NZ Transport Agency (NZTA) completed construction of a large timber pole retaining wall on Friday to stabilise a large slip, which was triggered by heavy rain in June. The new 100 metre-long retaining wall is made up of 86 timber poles that have been driven up to 15 metres deep down to bedrock, and held upright by 43 steel ground anchors beneath the highway.
NZTA Area Engineer, Gerhard van Blerk says he is confident that the new retaining wall will stop any further subsidence of SH23 in that location.
The completion of the retaining wall will now enable repairs to progress on two more recent slips in the saddle area of the Raglan Deviation area – one immediately east of the retaining wall, and one further west towards Raglan.
Investigation is currently underway to determine suitable repair solutions for both these slips. Repair works will commence after the school holiday period in early 2009, to minimise disruption to holiday traffic.
In the meantime, a 30km/h speed restriction will be in place through the slip section closest to Raglan.