列车荷载作用下渗漏隧道的长期非线性固结

Long-term nonlinear consolidation of soil around a shield tunnel with partially sealing linings under train loading

为研究列车荷载对地铁周边土体长期非线性固结的影响,以及其与隧道渗漏的共同作用,将列车荷载等效为矩形循环荷载,采用经典的土体非线性固结理论,以及衬砌与土体相对渗透性系数,得出列车荷载作用下局部渗漏隧道的非线性固结解析解.通过本文预测值与上海地铁实测数据的对比,验证了解析解的合理性.分析结果表明:列车荷载加剧了隧道上方地表长期沉降,衬砌渗漏程度越大,沉降增加量越大.本文解析解能较好模拟隧道周边土体的长期固结特性,为预测地铁隧道长期运营导致的地表沉降提供一个较为合理有效的方法.

The train loading is simplified as equivalent rectangular cyclic loading in this paper to investigate the influence of train loading on long-term deformation of soft soil around a shield tunnel. Based on the empirical relation between permeability and compressibility, the governing equation of nonlinear consolidation is established. Then the analytical solutions are derived after the partially sealing lining as boundary condition is considered by introducing a dimensionless relative parameter of soil-lining permeability. The rationality of corresponding analytical solutions is confirmed by the comparison among predictions of ground settlement by presented solution and field data from Shanghai Metro Line No. 1. The results show that the increment of ground settlement by train loading is positively correlated with partially sealing condition. The presented solutions provide a reasonable and effective tool for the prediction of long-term ground settlement by the operation of metro way.