Numerical Simulation Of Surface Subsidence And Plastic Zone On Tunnel Excavation

With the rapid development of the national economy, tunnel engineering is more and more and is becoming more and more important. Tunnel construction will inevitably lead to surface subsidence. The surface subsidence is to a certain extent, will affect the normal use of the buildings on the ground. Therefore, the study of surface subsidence is very necessary. The determination of plastic zone of tunnel excavation is very necessary to determine the tunnel lining or supporting scheme.The calculation method of tunnel construction is broadly divided into four categories: analytical method, empirical formula method, model experimental method and numerical method. With the rapid development of computer hardware and software technology and computing technology, the finite element method as the representative numerical method has been widely applied. The simulation of tunnel excavation by using finite element software is gradually become a common method. In this paper, the numerical simulation of tunnel excavation by using COMSOL Mulitiphysics software is done. The surface settlement of the tunnel excavation is calculated. The corresponding plastic zone is obtained.In this paper, the research background, research significance, research status both at home and abroad are briefly introduced. The research goal and the content of this paper are introduced. The constitutive relationship of tunnel excavation is briefly introduced. The basic equations and boundary conditions of elastoplastic boundary value problem are described. The principle and process of using COMSOL Multiphysics software simulation of tunnel excavation is given.By using COMSOL Multiphysics software to simulate the surface subsidence and the plastic zone shape of single-bore tunnel excavation with the circle or the city door form in the free soil and the bearing soil. By using COMSOL Multiphysics software to simulate the surface subsidence and the plastic zone shape of two-bore tunnel excavation with the circle or the city door form in the free soil and the bearing soil. The stress nephogram, the surface subsidence curves and the plastic zone schematic in each case is given.Through the work of this paper, in order to control the surface subsidence, to protect the ground buildings and to determine the tunnel lining or supporting scheme provides important reference basis, it is of great significance for tunnel excavation.