Underpinning works involving building new foundations beneath one of the piers of an elevated rail line will provide reinforcement and redistribute the load for tunneling to commence underneath.
The works by the Suburban Connect joint venture under the Clayton viaduct in Melbourne’s south-east are on the SRL East project, the first stage of Victoria’s Suburban Rail Loop (SRL) project, from Cheltenham to Box Hill.
The tunnel route of the SRL East project will pass under the elevated rail line at the point of the works so new foundations for the pier will help support the bridge’s weight, redistributing the load away from the new tunnel. The Tunnels South package for SRL East, is being delivered by the Suburban Connect JV, which comprises CPB Contractors, Acciona, and Ghella.
Suburban Connect’s contract includes 16 km of tunnels between Cheltenham and Glen Waverley, 55 cross passages two portal structures, and two station box excavations and supports.
Tunnel boring machines will be launched from a recycling site in Clarinda, with four TBMs to be used instead of six. A ‘ground freezing’ technique will also be used to build safety passages between the twin tunnels, allowing passages to be constructed below ground instead of from the surface.
The SRL will be a 90 km rail line linking every major train service from the Frankston Line to the Werribee Line via Melbourne Airport.
About the author
Desi Corbett
Desi is the Editor of Concrete in Australia, at the helm since December 2013, and our weekly news writer since 2016. Focused on concrete and construction for more than 11 years, her expertise in this field forms part of a journalism career spanning three decades. To get in touch please email desi@corbettcomms.com