News Articles | 2 May 2019

Tunnel boring machine (TBM) Grace and her crew reached another milestone earlier this week: completing 4.5km of tunnelling!

This brings Grace within 80 metres of Redcliffe Station, where she is expected to break through in the coming week. TBM Sandy, following the completion of repair works on her screw conveyor mid-April, is not far behind and about to hit the 4km mark.

Before the TBMs can break through into the station box they will need to tunnel through the dry box, an underground structure located adjacent to the station wall which will help correctly pressurise the TBMs breakthrough.

Once at Redcliffe, Grace and Sandy will undergo scheduled maintenance as well as be fitted with brand new screw conveyors, before continuing their journeys towards Bayswater.

Have your say!

Every six months we conduct market research so the community can provide feedback on the project. With significant progress now made across the project's 13 active construction sites, it is even more important that you have a chance to have your say.

The survey is a ‘health check’ for our team to gain insight and feedback from those who live nearby the works, so we can better understand what we do well and what we can improve on. It will take approximately 10 minutes to complete.

You can complete the survey by clicking here.

Home stretch for Bayswater dive structure

At Bayswater Junction 13 of the 18 sections forming the base slab of the dive structure have now been poured with concrete. The team is busy installing steel and waterproofing for the final five sections of the slab, which are located below the Midland Line overpass and interact with removal works of the redundant main drains. All concrete pours for the base slab are expected to be completed by the end of May.

While there is no above-ground construction in progress at the portal end of site, behind the scenes designers and engineers are working on plans for the installation of the portal's lift and stairwell, which will provide access in emergencies from track level to ground level. Construction is scheduled to commence mid-year.

Redcliffe Station ready to host TBMs

Over the past few months the crew at Redcliffe has been busy preparing the station box for the arrival of the TBMs. This work is now complete and all eyes are on TBM Grace to make her breakthrough.

The arrival of the TBMs will mark a change in activity at Redcliffe site, most significantly the start of 24-hour operations. A 32m-high electric tower crane has been erected onsite ready to begin lowering tunnel segments into the station box once the TBMs leave Redcliffe. Multi-service vehicles (MSVs) will then cart the segments through the tunnels to the TBMs.

At the site of the station’s future car park, the ground has been levelled and the first round of compaction completed. Drainage and electrical pit installation was also recently finalised, allowing for the base material layer to be placed. These works will continue to the end of May with sealing and asphalting to occur in June.

Multi-level works ongoing at Airport Central

Another project milestone approaching quickly is the installation of the 35m-long escalator at Airport Central Station. The escalator, which will take passengers from the Skybridge to the concourse level, will be installed in three sections and must be put in place before the construction of the roof structure can commence.

At concourse level the slab has been completely infilled at the eastern end. Once fully cured, the remaining temporary struts installed during the station box excavation will be removed. The same set of works will commence at the western end in the second half of the year.

And right at the bottom of the station box the platform area will really start to take shape this month as crews continue to cast the platform walls. Services will then be installed progressively before the area is backfilled.

Forrestfield Station a hive of activity

With the stowage building at the southern end of the site now constructed, work is focussing on the central and northern sections of the Forrestfield site.

At the portal end, and just above the tunnel entries, work has begun on the mezzanine level of the multi-storey portal building. Steel beams are being installed in preparation for the upcoming concrete pour, and the installation of door frames is also underway.

There is also a hive of activity at the station area in the centre of the site. Here, eight columns to support the suspended concourse slab have been erected on top of the station platform. With the columns in place, formwork is being installed ready for the suspended slab to be poured in the next two months.

Progress on emergency exit points

Given the length of the project's twin tunnels, additional infrastructure is required between the stations to allow safe egress to the ground level in the event of an emergency, and access to the tunnels for maintenance.

As such, three emergency egress shafts (EES), twelve tunnel-to-tunnel cross passages and three tunnel-to-egress shaft cross passages will be constructed along the alignment.

View a map of all cross passage and emergency egress shaft locations.

With all three EES now excavated, work is underway on the cross passage between Airport West EES and Tunnel One.

Work has also commenced on Cross Passage RAC, with the breakout of the tunnel segment in Tunnel One complete. Excavation to connect Tunnel One to Tunnel Two will now begin, with the works expected to take approximately six weeks.

View the cross passage and emergency egress shaft construction fact sheet.

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