Construction has started on Albert St’s first CRL tunnel box.
CRL contractor Connectus JV has started the base pour for the first of the 29 box sections of the tunnel.
The process of building the tunnel box sections involves a number of steps:
- A smooth surface needs to be constructed along the pile line, against which the tunnel walls can be poured. Steel mesh and pins are installed into the piles, followed by a sprayed concrete application known as ‘shotcreting’. The shotcreting team has already completed the first 44 metres section of the shotcrete surface.
- A base ‘blinding’ layer is poured to form a level and clean working surface. The first 44 metres of blinding has also been completed.
- Waterproofing membrane is then hung against the shotcrete surface and laid across the blinding layer.
- Steel reinforcement will be tied and formwork (temporary moulds into which concrete will be poured) installed as the pouring of the tunnel boxes progresses.
For the first concrete pour for the base slab of the tunnel box, the job required; about 15 workers, 25 concrete trucks and 109m3 of concrete. Today the team removes formwork and prepares the construction joints.
Videos - inside the trench
These steps will be followed until 350 metres of CRL tunnel is constructed down Albert St.
At the same time as the first pour, other works were going on:
- Fixing steel on slab 3
- Shotcreting on slab 5
- Lifting into the trench to install walers & struts at slab 8
- Rock bolting on slab 10
- Excavation and spoil removal from slab 12-19
- Service relocation at slabs 21 to 24