Abstract

The seepage force can cause failure of the underground excavations and openings that are lying below the groundwater table (GWT). The present research work aims to estimate the support pressure for peripheral stability of rectangular tunnel in anisotropic cohesionless soil below the GWT by using the lower bound finite element limit analysis and second-order conic programming. The seepage forces around the tunnel are computed from the total head distribution in the soil under steady-state seepage condition using finite element analysis. A uniform support pressure p_i is applied at the tunnel periphery to resist the active state collapse of soil. The effects of various parameters on the magnitude of the normalized support pressure at the tunnel periphery are studied thoroughly. Design equations are provided by conducting regression analysis with present numerical results.

摘要

渗流力会导致位于地下水位 (GWT) 以下的地下挖掘和开口失效。目前的研究工作旨在通过使用下界有限元极限分析和二阶圆锥规划来估算 GWT 以下各向异性无粘性土中矩形隧道周边稳定性的支护压力。隧道周围的渗流力是使用有限元分析从稳态渗流条件下土壤中的总水头分布计算得出的。均匀的支撑压力p _i应用于隧道周边，以抵抗土体的活性状态坍塌。深入研究了各种参数对隧道周边归一化支护压力大小的影响。通过对现有数值结果进行回归分析来提供设计方程式。