Finite Element Analysis And Simulation Of Tunnel Based On Fluid-solid Coupling Theory

Tunnel and underground projects of our country have achieved unprecedented progress in recent years, along with the development of hydraulic engineering and transportation in the western mountainous areas. Unlike the construction projects on the ground, the construction of underground engineering has its unique complexities which can be divided into two types, the one is the construction factors, the other is a series of complex geological and natural condition, such as karst region, high geostress or subsoil water level condition.Groundwater, as one of the natural factors, is a hidden trouble for tunnel safety, and should take the main responsibility for budget overruns and the difficulties of construction. The simplified seepage analysis calculation may not be appropriate, without considering fluid-structure interaction, so it is of great significance to study on seepage problem considering fluid-structure interaction.In this paper, the deformation and stress of tunnel surrounding rock were analyzed during the construction; the tunnel simulation model in the seepage field was built, under the schemes of water-exchange and no water-exchange with outside, the change rules of seepage flux were studied considering different ground water levels; the behaviors of deformation and stress were observed in the fluid-solid model by one-way coupling.The result show that: the simulation result accord with the general rule of stress-strain of tunnel, the seepage flux increases linearly as ground water level rise. The symmetry of the displacement and stress fields is broken in the fluid-solid model, and the general rule of stress-strain of tunnel no longer apply. The displacement and stress are larger at the right side wall and floor of tunnel, where should be concerned.