Last week 4-years of work reached a significant milestone on the 4-lane Delhi-Vadodara Expressway tunnel breaking through the pilot heading.Whilst just another tunnel breakthrough, this one involved excavating two 4km long, 22m span caverns and 10no. cross-passages through very poor fissile shales with low cover at the portals, a sandstone and siltstone hillside with limestone bands containing karst cavities charged with surface water having > 100m head.The final hurdle was excavating this below an existing stream down to 10m of…

The VSU team picked up “Tunnelling Project of the Year (up to $500M)” at the NCE International Tunnelling and Underground Space Awards. Following on from our the earlier post below, this weekend we have undertaken our first trial of drone based photogrammetry, 3D colourised point cloud and ‘traditional’ 3D LiDAR point cloud surveys in a disused tunnel. Led by Marco Invernici, the data will be processed this week to see how it can be used to automate condition assessments of…

We are very pleased to be appointed on the Mumbai Metro Line 3, Sahar Rd Crossover cavern to optimise design and delivery of this sprayed concrete lined excavation. We will be working with our partners Endacom and Normet to deliver – for the first time in India – a permanent, fibre reinforced SCL tunnel. The proposed alternative design will significantly reduce complexity, material cost and programme for the cavern by removing a number of shutters and significant quantity of conventional…