News Articles | 5 April 2019

A major milestone was celebrated this week with all tunnel segments required for the 8km twin-bored tunnels produced.

A total of 9098 rings - that's 54,588 segments - have been poured, moulded, steam cured, painted and tested at a purpose-built facility in Forrestfield. More than 4691 rings have already been permanently installed underground.

Click here to find out how the tunnel segments were made.

And there is more good news: Tunnel boring machine (TBM) Grace is on the move again! After investigations revealed a mechanical issue with the screw conveyors on the project's two TBMs earlier this year, Grace and Sandy were stopped for assessment and repair works.

With TBM Grace's screw conveyor repairs complete she was able to restart tunnelling on 26 March and is now on her way to Redcliffe Station. Repairs to TBM Sandy are ongoing, with our second TBM expected to recommence tunnelling in the coming weeks. 

Concrete works ongoing at Bayswater 

At Bayswater Junction the tenth section of the base slab for the 400m-long dive structure has been poured, with only eight more to go. 

Crews install around 70 tonnes of steel in preparation for each concrete pour. Preparation works take around two weeks per slab, and there is an average of one concrete pour every week. Interestingly, if the steel rods installed in each section were lined up, end to end, the total length would equate to around 21km of steel on average per section.

At the tunnel portal, where the TBMs will break through at the end of their underground journey, walers that were installed to support the adjoining d-walls are currently being removed. With the concrete slab complete at the portal end, the area is now structurally self-supporting.

Two parallel retaining walls are currently being constructed at the western end of the site – one to retain vegetation and the other to separate the rail reserve from the principal shared path (PSP). Both are expected to be finished by mid-year.

Redcliffe Station car park clearing complete

Most of the current construction activity at Redcliffe Station is taking place outside of the station box as preparation works for the arrival of the TBMs are almost complete. One of the last sets of works to be completed is the installation of the second sealing ring at the far side of the station box. The rings will assist the TBMs when they are relaunched at the western end of the station box after undergoing scheduled maintenance work.

The foundation slab for the tower crane was completed in March and the erection of the 32m-high crane is currently in progress. Once the TBMs leave Redcliffe, the crane will become operational 24/7 as it will be used to lower tunnel segments into the station box.

The station’s car park, located near Central Avenue and Second Street, has been completely cleared of all vegetation and debris allow for backfilling (to pavement level) to begin. Drainage works for the car park have commenced and asphalting will be the next major activity to follow.

Escalator landing installed at Airport Central

Construction of the ground slab for Airport Central Station is progressing well with waterproofing and other preparations ongoing section by section. The passenger stairwell walls have been erected to about halfway between base slab and ground level. Once complete the structure will assist in supporting the ground slab.

Steel fixing for the concourse slab and formwork for the escalator pits is continuing. Excitingly, the main passenger escalator for the station is due to arrive in May. The escalator will be installed before the erection of the station’s main roof. Last week the landing for the escalator was successfully craned into position and affixed to the elevated walkway level.

Forrestfield Station works on track

Things are really starting to take shape at the southern end of the Forrestfield Station site where the 130m-long stowage platform slabs have been completed and the stowage building is fully enclosed following the installation of the roof and building’s gutters. Construction is now focused on the installation of building services.

At the portal end of the site, and just above the tunnel entries, construction is progressing at a steady pace as brickwork for the multi-storey portal building is being finalised at plant level. In the coming week structural steel will be installed, beginning construction up to mezzanine level. Following this the base slab for the mezzanine level will be constructed atop the structural steel.

Within the actual station area installation of electrical and communication cables is ongoing. Over the next couple of weeks the area will be prepared for the installation of structural steel columns that will eventually support the suspended concourse level slab to be constructed in May.

Last month three tilt-up panels were installed in the gap of the station‘s retaining wall. These 8m-high panels, supported by four counterforts, were required before backfilling could take place so the area would be ready to support the sixth section of the concourse slab.

View a map of how we expect the area around Forrestfield Station to look post-construction.

A breakthrough at Airport West EES

Waterproofing for the base slab inside the Wright Crescent emergency egress shaft (EES) was completed late-March, enabling the base slab to be poured. Outside the shaft the construction of the ground slab is ongoing with the installation of conduits for services such as power, water and firefighting systems.

At Airport West EES excavation has been completed between the shaft and Tunnel One. Waterproofing works to prepare for the construction of the cross passage base slab are underway and the entire cross passage is scheduled to be completed by the end of the month. 

Works at Abernethy Road EES will ramp up again once the steel elements for the lifts and stairs arrive in May.

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