Two giant drilling rigs will be parked at the Bayfair roundabout for the next six months as a key construction milestone gets under way in the Bay Link project.
Significant ground improvement works were under way at the Bayfair roundabout, a key milestone for the Bay Link project to move forward with construction of the new underpass and the State Highway 2 flyover bridge.
Next week, there will be a partial closure of the roundabout that could cause some delay for motorists.
Waka Kotahi NZ Transport Agency Portfolio Delivery Manager Jo Wilton said after the uncertainty created with the unresponsive pumice layer, it was great for the project to reach this point with a plan and progress.
"The design for the ground improvements needed altering after the pumice layer in the area was not performing as we expected. The lattice piling framework will provide further stability and limit liquefaction during an earthquake," she said.
Due to the sandy soils and high-water table in the area, around 5600 stone columns have already been installed throughout the site.
Two giant drilling rigs, weighing approximately 72 tonnes each and up to 25 metres high, will be located on-site for around six months.
"Installing the lattice framework involves overlapping concrete columns to create a sealed wall. It is estimated 9000m3 of concrete will be poured - equalling more than 21600 tonne, which will be delivered by around 1800 truck movements," she said.
She said they had worked closely with Tauranga Airport to ensure the height of the rigs' masts did not intrude on the flight path.
"Working alongside live traffic lanes also means the safety of motorists, members of the public and road workers is paramount. As part of this, the size of the Bayfair roundabout will increase to accommodate a larger construction zone."
The first of two changes to the Bayfair roundabout is anticipated to take place next week and will involve a partial closure of the roundabout.
The piling works will mainly occur during the day and the ground improvements work may generate some noise and vibration.