Study on upper-bound limit method of face stability of shield tunnel with high-water pressure

Abstract:

Based on the upper-bound limit method, theoretical formula of the minimum support pressure to maintain the face stability of the homogeneous soil tunnel under high-water level condition are deduced for the first time. Taking advantage of the soil thickness-weighted average method, the multi-layered soil parameters and the water pressure are to simplify the analysis, then the theoretical formula above can be applied to evaluate the face stability of the multi-layered soil cross-river tunnel and estimate the support pressure of the cross-river tunnel project. With the Shanghai Yangtze River Tunnel and the Nanjing Yangtze River Tunnel for example, limit support pressures of face were calculated by using the theoretical formula, and the calculated results has achieved a good agreement with the previous studies and engineering practice.