A big pour at Benmore Substation
10 September 2010
Transpower’s HVDC Pole 3 project met a major milestone on Tuesday, 31 August at Benmore Substation when 340 cubic metres of foundation concrete was poured. It took 11 hours, around 70 truck loads and 80 to 100 tonnes of reinforcing steel to form the basement floor for a new four-storey building.
Peter Griffiths, Programme Director for the Pole 3 Project says the pour was significant for the project. “To have achieved a successful pour in such a remote site was the culmination of good planning and risk management.”
“The first foundation pour represents the beginning of construction of the new Pole 3 assets and it’s a significant event for the project.”
The foundation includes large reinforced blocks that bearings and sliders will go on top of, all of which form part of earthquake proofing to allow the building to withstand a one-in-2,500-year seismic event. The building will house transformers, three new, state-of-the-art thyristor converters, a control room and other electrical equipment.
The recent events in Christchurch highlight the need of good seismic design, which has been an integral part of the project’s planning from the outset.
A mobile batching plant was set up on the east bank of the Otematata River by Allied Concrete for the pouring and will remain in place for future pours. A constant stream of trucks ferried the concrete from the plant to the substation, where it was fed into a long-reach concrete pump to form the 45m long, 15m wide and half a metre deep foundation.
A marquee was needed to protect the fresh concrete from the environment and heaters kept the concrete at a surface temperature of about 10 degrees.