隧道开挖问题中的流固耦合模型及数值模拟

隧道工程中的地下水问题是富水地层中普遍存在的重要问题，地下水流动对隧道围岩稳定性有重要影响。给出了描述隧道开挖过程中力学与水力特征及表征方法，根据岩体的基本结构特征及代表性单元体（REV）是否存在提出了流固耦合模型的建立方法；提出了隧道水力耦合数值分析中的耦合计算模型的建立方法；利用数值法研究了隧道开挖渗流与应力耦合问题，得到变形和渗流场的变化规律。结果表明，隧道开挖引起的渗流影响边界大于力学影响边界，由于渗流引起的渗流力增加了围岩的应力、位移，从围岩-支护结构共同作用原理考虑，进行隧道支护结构设计时是应该考虑渗流效应的。

Hydromechanical coupling model and numerical simulation of tunnel excavation

The groundwater problem is a key issue which affects stability of the surrounding rock in tunnel engineering. A method is proposed to depict mechanical and hydraulic behavior of the tunnel ground by tunnel excavation. Based on structure of rock mass and concept of representative element volume(REV), the methods of hydromechanical coupling model is proposed. Relevant methods of establishing tunnel excavation hydromechanical coupling mathematical models are proposed. The analysis results indicate the influence boundary of stress disturbed is smaller than that of seepage disturbed boundary. The seepage forces caused seepage increase stresses and deformations in tunnel ground. According to the interaction principle between ground and support structure, the seepage effects should be considered in tunnel support structure design.