Karangahape Works Update
CRL Link Alliance Karangahape Station Drone Footage July 2021
Work is advancing over at the two sites for Karanghape Station – Mercury Lane and Beresford Square.
Progress in Mercury Lane
Excavation for the B2 level was completed during this month, with the team now excavating to the deepest floor, B7. Once this level is reached, the construction method will change to ‘bottom up’, meaning the remainder of levels will be built on the way back up.
From B2 to B7 16,000 cubic metres of spoil will be removed, equal to the volume of 6.5 Olympic-sized swimming pools.
Heavy machinery (pictured), steel reinforcement bars and shutters will be lowered to each level from a crane above.
Progress in Beresford Square
Excavation for B2 has been completed and steel fixing will be completed next month. Once the steel fixing is completed, two of three concrete pours will be left to finish this level (completed by mid-August).
B2 concrete pour
The ‘top down’ method will continue until B4, with the excavation of B3 beginning soon. From B4-B7 the construction approach will switch to ‘bottoms up’ similarly to Mercury Lane.
The temporary decking has been completed allowing movement of the crane and trucks to drive over the opening and be loaded with spoil. The cavern beside the temporary deck will be the future site of the entrance, escalators, and lifts.
Tunnel Boring Machine (TBM)
The Dame Whina Cooper TBM, is expected to cross under the southern motorway in August, arriving in Karangahape in September. Commuters on the motorway will be blissfully unaware of what is happening beneath them as the earth pressure balanced TBM works away.
An earth pressure balanced TBM controls and balances the pressure of the earth it excavates which stabilises the tunnel face and reduces any possibility of settlement occurring.
To see the TBM’s progress, you can view the online TBM tracker via www.digcrl.co.nz.