In Albert Street, construction of the first tunnel box is starting.
It took three days to install the first 12 metres of the waterproofing.
The first step of the works was to place a first layer on the wall and floor.
This material is called filter cloth. It will protect the waterproofing membrane from perforation by the concrete.
Once installed, the waterproofing membrane is placed on top.
Meanwhile, bulk excavation of the cut-and-cover trench on Albert Street is continuing towards the Customs Street intersection.
The construction process included installing steel mesh and pin into the wall of the trench for temporary rock support.
This is followed by ‘shotcreting’: this means spray-concreting a smooth surface for the waterproofing membrane of the tunnel box. The shotcreting team is currently completing the first 44 metres section of wall.
The last preparation step is the ‘blinding layer’: pouring concrete on the floor of the trench to form a flat, smooth layer for the concrete slab that holds the tunnel rails. The first 44 metres of blinding is already complete.
The team then started the construction of 29 sections of tunnel box, each 12 metres long.
The waterproofing membrane wasinstalled on the floor and walls, steel reinforcement is fixed for the base slab, and formwork installed before finally pouring tunnel concrete.
Once about 60 metres of the tunnel box is constructed, the team can start backfilling.
These steps will be followed, stage after stage, for approximately 350 metres of tunnel.
In the second half of the year, the Albert Street trench excavation will be completed and connected to the Precinct Properties site on the corner of Customs and Lower Albert Streets.
The tunnel box construction will continue all year, following behind the excavation.
By mid-year, the Albert Street trench will start to be backfilled between Wyndham and Swanson Streets and the first portion of road reinstatement is expected to start at that location before the end of the year.
View drone footage from above Albert Street
Here are some recent photos of the trench work
This is how the Precinct Fletchers Commercial Bay tunnel development is looking
You can view the Albert St trench work at our pedestrian bridges on Albert St. They're at Swanson St and outside the Shakespeare Hotel.