To support the specified construction sequence, PERI’s engineers designed two carriages which enabled the site team to cast the walls and roof slab simultaneously, ultimately accelerating the programme. This comprised four units in total, two for the wall and two for the roof.
The carriages are designed to reduce material, manual labour and cranage as the main operations such as striking, positioning and travelling are completed hydraulically.
The wall forms are built from special modular steel panels. Each set is designed to build 20m-long and 7.5m-high walls.
The panels are suspended from a carriage which is designed using off-the-shelf components from PERI’s VARIOKIT range, with some specially fabricated connection parts. VARIOKIT rails provided additional support for the formwork, reducing through ties to less than half the quantity required in a traditional panel system.
Hydraulic operations have replaced a lot of the falsework which would usually support a slab pour this deep. In addition to material, automation has also eliminated labour-intensive assembly and dismantling operations on this project, which would require multiple operatives working at height.
Following on from the installation of the roof traveller, the next steps will be pro-gressing the tunnel so all three elements – base slab, tunnel walls and roof slab progress concurrently without conflicting. Tunnel construction is expected to be completed by February 2025.
Special steel formwork was ideal for this project as the forms can be reused up to 30 times, so there is an obvious material-saving advantage in addition to time-savings, as panels do not need refacing unlike a plywood faced system would. We’re very pleased that we’ve been able to reduce material wastage and contribute to reduced carbon emissions, knowing that these steel panels can be reused for future projects without needing to be refaced.
Interested in how PERI can support your next project?
Call us on 01788 861600 to discuss your requirements further.