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Construction work changes that could affect you are listed in our
Looking like a tunnel
14 June 2018
This is how the Albert Street tunnel trench is looking today.
Pile cap construction
12 June 2018
Outside the Chief Post Office, excavations on Lower Queen Street are underway for construction of a pile cap on the new secant piles.
Albert Street- drone footage
12 June 2018
A three-minute video showing drone and underground footage of the current Connectus construction of the tunnel trench up Albert Street.
Fifth wall poured
11 June 2018
In the Albert Street tunnel trench, the Connectus construction team (McConnell Dowell and Downer) has poured the 5th wall, meaning 60 metres of the tunnel walls are now complete.
Another Connectus crew is preparing for the first sections of the roof and tunnel. You can see the roof formwork.
CPO floor excavations underway
28 May 2018
Excavations of the temporary former Chief Post Office floor are now underway.
During the next two months, the temporary floor and polystyrene blocks will be removed down to B1 level.
These are preparation works before the bulk tunnel excavation works can commence late July.
Secant piling finished
24 May 2018
Another milestone bringing us closer to construction of the City Rail Link tunnels that will make Britomart a through station.
It’s the completion of secant piling which has been happening in Lower Queen Street outside the former Chief Post Office (Britomart).
The secant pile walls will connect the excavation under Britomart to the excavation at Precinct Properties’ Commercial Bay development on the other side of Lower Queen St, where CRL tunnel boxes are being constructed. 70 secant piles had to be installed and the last one will be done tomorrow.
Secant piling is construction of intersecting reinforced concrete piles. These piles lock together for strength and control any groundwater ingress into the tunnel excavation. A 70 tonne piling rig was brought in for the drilling.
Start on middle wall of tunnel box
03 May 2018
The middle wall of the first 12 metres tunnel box in Albert Street is presently being poured by the Connectus team (McConnell Dowell and Downer). The outer walls were done on Tuesday.
The middle wall is not as wide as the outer walls with a width of 460mm (600mm for the outer wall). It is slightly taller with a height of 5 metres(4.6m for the outer wall). It requires less concrete with 28m3 of concrete or 6 concrete trucks instead of the 60m3 used for the outer walls.
The steel formworks’ weight is doubled for the middle wall with a weight of 20 tonnes. The roof is scheduled for the end of this month.
Albert Street tunnel box milestone
01 May 2018
The CRL Connectus team (McConnell Dowell and Downer) is pouring the first 12 metres outer walls of the tunnel box in Albert Street.
The team is pouring two walls, the east and west wall – the middle one will be poured later in the week and the roof is scheduled for end of May.
60m3 of concrete is needed for the two walls- that comes in 15 concrete trucks. The eastern and western wall are 600mm wide and 4.66 metres high each. The steel formworks weigh 10 tonnes for each outer wall.
CPO building load transfer
01 May 2018
We’re a step closer to be able to start tunnel excavations in the former Chief Post Office (CPO) building.
Those excavations will turn Britomart into a through tunnel.
Contract one of the CRL works involves Downer NZ and Soletanche Bachy (DSBJV) progressing the CRL work through and under Britomart Station and Queen Street to the former Downtown Shopping Centre site which is now Precinct Properties Commercial Bay development.
They've achieved a new milestone.
This was that the first area of the CPO building that has been load transferred onto one of the structural steel underpinning frames.
There are 12 frames.
Why this is significant is because once all the load transfers are completed, we can then start tunnel excavations safely.
NORTHERN: Underpinning beams at the northern end of the former Chief Post office
The weight of the building is carried by its columns down into the building foundations.
Before excavation of the rail tunnels can commence, a number of these foundations need to be removed – so the associated weight of the building firstly has to be transferred onto the underpinning frames.
Each affected column is clamped by a steel collar which sits upon a steel beam located either side of the column. A hydraulic jack is located beneath each corner of the collar (four jacks in total per collar) and these jacks are used to exert a force on the underside of the collar equivalent to the building weight carried by the column.
Each underpinning frame consists of two collars and the two beams. The beams span between two rows of diaphragm walls which were installed earlier during the project and are fixed to the capping beams which sit upon the diaphragm walls. Each frame supports two CPO building columns and the weight carried by both columns are transferred concurrently onto the frame during the load transfer for that frame.
SOUTHERN: Underpinning beams at the southern end of the former Chief Post Office
During load transfer, the force exerted by each jack is slowly increased by increasing the hydraulic pressure within the jack and it is closely monitored along with any ‘lift off’ (displacement) experienced by the column. When the jacks exert a maximum specified force (predetermined by calculating the weight of the building carried by each of the two columns) or the column experiences ‘lift off’, the load transfer is complete.
Following construction of the rail tunnels and the subsequent re-build of the CPO building foundations, the weight carried by each column will be transferred back into the building foundations and the underpinning structures will be removed.
All heritage values of the former CPO building have to be maintained - the project is working closely with the Heritage New Zealand.
In January 2017, the Queen Street entrances to the Britomart Transport Centre closed for three years so that the CRL tunnelling work underneath could be done.
Time-lapse videos
24 April 2018
These videos show construction in the former CPO (Britomart), outside the CPO in Lower Queen Street and the tunnel construction at Precinct's Commercial Bay development.
CRL tunnel box construction to start on Albert St trench
23 April 2018
At the Wyndham Street end, contractor Connectus JV is lowering 16 temporary formworks (frames) to the bottom of the trench, which will be used to cast CRL tunnel walls.
Construction starts this week of the first 12-metre long wall section of CRL tunnels within the Albert Street trench.
Meanwhile, the bulk excavation of the Albert Street trench continues towards the Customs Street intersection.
The excavation and tunnel box construction is expected to be completed by the end of this year, at which time the Albert St tunnels will be joined to those constructed under the Commercial Bay development site.
Britomart construction works update
23 April 2018
Work continues in and around the historic CPO building to prepare for construction of the CRL tunnels that will make Britomart a through station.
UNDERPINNING: The beams form an important part of the building support system during tunnel excavation
Inside the CPO, installation of steel underpinning beams continues. The beams form an important part of the building support system during tunnel excavation.
Guide walls have been constructed through Lower Queen St to prepare for secant piling. Made of reinforced concrete, these piles lock together for strength and to control any groundwater ingress into the tunnel excavation.
The secant pile walls will connect the excavation under Britomart to the one at Precinct Properties’ Commercial Bay development on the other side of Lower Queen St, where CRL tunnel boxes are already being constructed.
Tunnel construction beneath the CPO and across Lower Queen St is expected to begin at the end of this year and be completed in 2019.
Mount Eden work starting
10 April 2018
Work is about to start on CRL’s C6 contract to demolish two buildings and divert a 400-metre section of stormwater main at Mt Eden.
The stormwater main must be diverted before any future station works at Mt Eden, as the alignment of the existing watermain clashes with the location of the future CRL tunnels at Mt Eden.
Before the stormwater diversion, CRL needs to demolish apartments at 26 Mt Eden Road and the former Hyde Group building on the corner of Nikau and Ruru Streets. A specialist demolition contractor is undertaking this work, which will be completed by May.
After demolition, shafts will be dug at Water and Ruru Streets. They will launch and receive the micro tunnel boring machine that will install the replacement stormwater line.
The tunnel will be completed in a single drive from Water to Ruru. A third shaft at Mt Eden Road will provide future access to the watermain via a manhole.
This work is expected to be completed by autumn 2019.
The Stormwater route
The shafts:
Water St (launch)
- 16m deep secant pile construction
- 8.5m internal diameter
Mt Eden Rd (access)
- 18m deep
- 2.5m internal diameter
Ruru St (receiving)
- 15m deep shaft
- 9.4m internal diameter
Work programme
April 2018 Demolition works
May/June 2018 Shaft works, followed by pipe-jacking
Autumn 2019 Expected completion
Pollutant traps
In addition to the stormwater realignment, pollutant traps will be installed at Boston and Normandy Roads as part of the stormwater network improvements for Auckland. They will capture large and non-biodegradable waste such as litter and coarse sediment to prevent it reaching waterways.
Boston Road April-May 2018
Normanby Road: Spring 2018
Each trap takes about four weeks to install.
Time-lapse videos
19 March 2018
These videos show construction in the former CPO (Britomart), outside the CPO in Lower Queen Street and the tunnel construction at Precinct's Commercial Bay development.
Secant piling underway
05 March 2018
Guide walls have been constructed through Lower Queen Street. These are for the secant piling (construction of intersecting reinforced concrete piles) which is getting underway.
Made of reinforced concrete, these piles lock together for strength and to control any groundwater ingress into the tunnel excavation.
The secant pile walls will connect the excavation under Britomart to the excavation at Precinct Properties’ Commercial Bay development on the other side of Lower Queen St, where CRL tunnel boxes are being constructed.
The pits are excavated to the depth of the polystyrene blocks. The blocks are shaped and interlaced together in the pit with rebar cages either side. Concrete is then poured into the cages around the polystyrene and left to set. This forms the guide walls.
To construct the secant piles, a new 70 tonne piling rig has been brought in and will start by drilling into each polystyrene section to guide the drill in the correct direction and then continue drilling down to the depth of 16m. Reinforcing will be place and concrete poured to lock the piles together tightly. There will be a total of 70 piles.
Tunnel Box Pour
01 March 2018
The construction of the Albert St tunnel box is going well. The first 12 metres of waterproofing has been completed for the first slab so reinforcing works have just started.
The first slab will be completed on Saturday and the first pour will begin on Monday.
Two tonnes bundles have been individually lifted between the struts to the trench floor by contractor CRS Ltd. It takes 8 steel fixers 5 days to tie together one floor slab (12 metres). 20 Tonnes of steel are used for the first slab.
Sandrine leaves
14 February 2018
She's off on a long journey home.
Sandrine heads back to France. The bright red 90-tonne piling rig has finished working around the historic CPO (Britomart) building for contractor Downer Soletanche-Bachy JV.
Thanks for your great work Sandrine and all those who worked with her.
Albert Street Trench Construction Starts
14 February 2018
In Albert Street, construction of the first tunnel box is starting.
It takes three days to install the first 12 metres of the waterproofing.
Final concrete pour for D-wall
31 January 2018
Downer Soletanche JV workers have begun the final concrete pour for the 64th and final diaphragm wall (D-wall) in the CPO. The walls were required to support the CRL tunnel excavation under Britomart Station.
The D-walls not only provide soil retention and control groundwater ingress but support the weight of the historic building during tunnel construction.
This also means the end of the work there for the big piling rig Sandrine. The 90-tonne compact rig Sandrine moved into the CPO in September 2017 to dig those 15 to 20-metre-deep wall panels that form the structural support for the CRL tunnels.
