White Papers
Overcoming Extreme Tunneling Conditions in Vietnam’s Longest Tunnel
Vietnam’s Thuong Kon Tum Hydroelectric project is a 17.4 km headrace tunnel that will be the country’s longest once complete. A section of the tunnel was excavated by a 4.5 m diameter Main Beam TBM in granitic rock up to 250 MPa UCS. Started in 2012, the project’s original contractor left due to non-satisfactory performance. In 2016, the contract to refurbish the TBM and excavate the remaining 10.45 km of tunnel was awarded to a joint venture of Robbins and a local contractor. Robbins was fully responsible for the TBM operation, including supplying operational crews. The crew overcame massive granitic rock, fault zones gushing water at 600 l/s, and difficult conditions. In under two years, the TBM advanced from a standstill at 15 percent project completion to 85 percent complete. This paper addresses the refurbishment of the TBM in the tunnel, the work to streamline operation, and challenges faced.
- Long Haul TBM: Use of a Rebuilt Main Beam Machine at the DigIndy Tunnel System in Indianapolis, IN
- Evaluating TBM Design and Performance, 30 Years Apart: The Lesotho Highlands Water Tunnel, Phase 1 and Phase 2
- Use of a Tunnel Boring Machine on Nepal’s First and Second TBM-Driven Tunnels
- Record-Setting Large Diameter Mixed Ground Tunneling in Turkey: The Eşme-Salihli Railway Tunnel
- Lessons Learned During Excavation of the Incredibly Challenging Yin Han Ji Wei Water Diversion Tunnel