Tunnel on track to ease traffic

Picture / Herald on Sunday

Work is on schedule for the $340 million Victoria Park Tunnel project.

The 440m long cut-and-cover tunnel project is one part of a series of projects collectively known as the Central Motorway Improvements (CMI).

Once finished, the tunnel will take about 100,000 vehicles in its three northbound lanes from early 2012.

The tunnel will take the pressure off the St Marys Bay section of State Highway 1, which is currently used by about 200,000 vehicles a day.

Work is being directed under the Victoria Park Alliance that includes Fletcher Construction and the New Zealand Transport Agency. Project liaison manager Darren Utting said work was taking place at five different locations.

Utting said the work had progressed well thanks to the ground excavations being easier than expected.

About 280m of the tunnel walls have been completed, 80m of which are in the Victoria Park section of Beaumont St, parallel with the motorway flyover.

Utting said the walls were each about 1m thick, about 20m apart and stand between 14-25m deep into the ground.

A total of 439 of the required 1039 concrete piles have also been inserted at the base of the tunnel and stand as much as 18m in the ground. Each one takes about a day to place.

Up to 420 people are working on the project.

Before tunnelling began, workers had to relocate 2km of water mains and 500m of stormwater calvert.

By the end of the tunnel project about 150,000m3 of dirt would have been moved from the site.

When completed in 2012 the tunnel will provide three lanes for northbound traffic and convert the existing motorway viaduct to four southbound lanes.