高水压条件下盾构隧道开挖面极限上限法研究

Study on Upper-bound Limit Method of Face Stability of Shield Tunnel with High-water Pressure

基于极限分析上限法,首次推导了高水压下维持均质土隧道开挖面稳定的最小支护压力解析解公式.并利用土层厚度加权平均法,对多层土体参数和水压力进行了简化分析,从而可将上述解析解公式应用于多层土越江隧道开挖面稳定性评价中,可为越江盾构隧道推进工程中估计前方支护压力的参考.最后,结合上海长江隧道和南京长江隧道实例,利用推导的解析解公式对越江隧道开挖面极限支护压力进行了计算,并将计算结果与前人研究和工程实际进行了对比分析.

Based on the upper-bound limit method,theoretical formula of the minimum support pressure to maintain the face stability of the homogeneous soil tunnel on high-water level condition was deduced for the first time.With the soil thickness-weighted average method,the multi-layered soil parameters and the water pressure were simplified and analyzed.The above theoretical formula was applied to evaluating the face stability of the multi-layered soil cross-river tunnel and the support pressure of the cross-river tunnel project.By taking Shanghai Yangtze River Tunnel and the Nanjing Yangtze River Tunnel for example,limit support pressures of face were calculated by the theoretical formula,and the calculated results achieved a good agreement with the previous studies and engineering practice.