土压盾构施工引起的土层应力-变形分析

Analysis of Soil Stress-deformation Behavior Caused by Earth Pressure Balanced Shield

为对土压盾构施工过程中土的应力-变形进行研究,利用大型有限元分析软件PLAXIS建立了关于土压盾构机在隧道开挖过程中对地表沉降的影响模型,并运用该模型对盾构过程中土层的应力状态和排水情况进行分析,并在此基础上通过考虑盾构机的推进速度、土的固结系数、隧道的覆土厚度和隧道断面4个因素,通过参数试验得出关于判断隧道开挖过程中土层排水情况的方程,并根据具体的隧道工程和地质条件进行数值模拟对方程进行验证。结果表明,地表沉降预测值与实测值吻合较好。

This paper deals with the effects of earth pressure balanced tunneling on the stress path and drainage condition of the soil during tunnel advancement by using PLAXIS. By taking into account the three significant factors of advance rate of the tunnel face, consolidation coefficient of the soil, overburden depth of the tunnel, a parametric study is conducted and a numerical experimental equation proposed for determining drained or undrained soil condition during shield tunnel advancement. Finally, a case study of EPB tunneling is introduced. By using the case study data and results of EPB tunneling on stress path analyses, the proposed equation is verified.