GFWAust carried out a trial demonstrating the effectivemness of the DryTech injection system to prevent water ingress through cracks in the concrete lining.
Melbourne Underground Rail Loop (MURL) was constructed between 1971and 1985.
The loop comprises four underground railway lines beneath the centre of Melbourne. Loop services serve the three underground stations (Parliament, Melbourne Central and Flagstaff) plus Southern Cross and Flinders Street stations. Each underground loop station has four platforms
The running tunnels were constructed by tunnel boring machine (TBM) with installation of steel ribs and a primary shotcrete lining to support the Silurian mudstone. The secondary final lining consists of 450mm thick cast in-situ concrete with no waterproof membrane.
The lining exhibits longitudinal and circumferential cracks, some of which have minor water ingress. GFWAust were appointed to carry out a remediation trial to repair the cracks and seal off the water ingress. GFWAust demonstrated the effectiveness of the DryTech chemical injection system together with a specialist cement mortar and polyurethane. The trial was successfully completed over a weekend shutdown during 12 hour nightshifts fitting in with other priority work.