Piling is a common technique used to bore steel and concrete support structures below ground to support retaining walls and deep excavations, such as the tunnel shaft. It is also used to construct the footings of acoustic sheds and noise hoardings around the NorthConnex sites. At NorthConnex, the project team use bored piling which involves an auger (similar to a large drill bit) drilling into the soil to create a hole.
Piling activities include:
- Mobilising piling rigs and support equipment such as concrete trucks to the compound (oversized loads will be delivered out of hours due to road use permits)
- Surveying pile centres and offsets
- Drilling, cleaning and verifying holes
- Installing steel cage pile reinforcement and steel posts
- Placing concrete. Once piles are in place shaft excavation can begin.