Watercare – Jonathan Graham
Harrison Grierson – Peter Evans
Construction of a large underground pump station and storage tank at Brigham Creek Rd, Whenuapai. Project timeframe is extremely tight and requires thorough planning and coordination of critical activities. Involves extensive temporary works, construction of concrete walls up to 7.7m tall, mechanical and electrical installation, siteworks and landscaping.
Earthworks; Erosion & Sediment Control; pump station construction; deep excavation; precast concrete; mechanical installation; electrical installation
This project followed the Hobsonville PS 70, and is located on Brighams Creek Rd. The design is similar to Hobsonville PS70, except that it has one wetwell and drywell, and is deeper at 7.7m.
The deep section of the excavation was retained using a shotcrete wall, and over 300 soil nails. The shallow section used more conventional timber retaining. As the pump station is founded on rock, only tension piles were required, and these were double reidbars grouted into 400dia piles. The structure consists of precast panels stitched together with heavily reinforced infill joints.
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