Abstract

‘URUP’ tunnelling, developed by OBAYASHI in Japan, is an innovative shaft-less shield technology. The TBM is launched/arrives at ground level and drives under shallow cover without ground treatment. The result is significant cost savings, reduced construction time and reduced environmental impact. The incentive for the development of this new tunnelling concept was the need for tunnel construction in congested areas, challenging ground conditions and stringent physical and environmental constraints. The critical issues in ‘URUP’ technology are mainly tunnel face stability and ground movement control. Innovative methods are used that have been developed by OBAYASHI through extensive technical research and development. The new concept was proven through a verification project and adopted by several projects in Japan, which have been successfully constructed. These projects involved circular TBMs with diameters ranging from 2.1m up to 13.6m, an oval shape open-face TBM as well as a rectangular TBM . The presentation will describe how the URUP concept was developed, mechanisms of ground control under shallow cover and review projects where it has been successfully used.