Work and design of a new tunneling method 'SENS' to unconsolidated ground

The sambonihara Tunnel is on the Tohoku Shinkansen Line. The geology of this tunneling site mainly consists of alternating layers of unconsolidated sandy soil under high hydraulic preassures and cohesive soil. This tunnel was excavated using the NATM, but the tunnel face collapsed twice, preventing the tunnel construction from advancing as scheduled. We therefore conducted an-depth study to develop a new tunneling technique, aimed at improving efficiency and safety of the work. The new tunneling method uses a standard earth and mud pressure shield to maintain face stability and ensure good excavating capability. This paper oulines the construction and design of the linings selected for this tunneling practice. LOKASI: Ruang Koleksi Umum Rak: 2