The last pile has been dug on Albert Street as part of the CRL project – 362 piles have now been dug between Customs Street and Wyndham Street.
'Gomer' – the nine-storey-high piling rig affectionately named after 1960s TV character Gomer Pyle – began piling in September 2016. Each pile was drilled to a depth of 20m and filled with reinforced concrete, which will support the trench walls within which the CRL's twin tunnels will be constructed.
CRL Project Director Chris Meale says, "Moving now to the excavation stage is an exciting time for the project and takes us a step further in the construction of the CRL for Auckland."
Connectus, the project's contractor, is now forming the concrete capping beams which will be placed on top of the piles to tie them together. Steel I beams will then span the width of the trench to brace the piles. This marks the start of construction of the 'cut and cover' tunnels across Customs Street and up Albert Street to Wyndham Street.
The cut and cover methodology is being used in this part of the project due to the geology, shallow position of the tunnel and proximity of underground utilities. It involves the excavation of a deep trench between the rows of piles and construction of the tunnel structure (essentially a concrete box), after which the trench will be backfilled and the road reinstated. This work is due to be completed in late 2018.
New stormwater main
Last week, the tunnel boring machine (TBM) simultaneously excavating and installing a new stormwater main 18 metres under Albert Street, finished its 500-metre journey between Swanson and Wellesley Streets.
Now located 10 metres east of its original alignment, the new stormwater pipe will allow the CRL tunnels to be constructed under Albert Street without interference to the stormwater system, while also helping to future-proof Auckland's stormwater capacity.