Whangarei Civic Centre

Spiral Drillers were contracted to complete 78 x piles for the construction of the new Whangarei Civic Centre.

The pile design consisted of driven UC piles with three different section sizes: 250UC90, 310UC97 and 310UC118. Piles were driven using our Junttan PM25 fixed mast Pile Driving Rig.

The site location involved a basalt float of varying thickness. Piles were required to either found on the basalt, predrill through and found on the sandstone or found directly on sandstone. This was a risk for the client due to unknown fringe and thickness of the basalt layer.

Spiral Drillers installed temporary casings up to 24 metres deep, bored down and cored through the basalt layer and then drove a UC to the required load capacity. The temporary casings were then backfilled and retrieved using a vibro hammer. Discussions early on with the Engineer to determine the design intent, allowed Spiral Drillers to come up with a clever approach to the work and minimise the amount of coring required to be completed on the project. This enabled programme acceleration and cost savings for our Client.