A predicting model for ground movement induced by non-uniform convergence of tunnel

Stochastic Medium Model(SMM) was widely used for predicting ground movement induced by tunneling in China.A uniform convergence mode was assumed in this model for the transversal section of tunnel after excavation.According to the observed convergence mode of tunnel,a non-uniform convergence mode was introduced to the SMM method to achieve a better prediction of the ground deformation,and the integral limits for various shapes of cross section,such as the circular,elliptical,rectangular and horse-shoe shaped tunnel were deduced.Based on some case studies,it was found that the uniform convergence assumption cause considerable error for shallow tunnels,so it was important to consider a proper convergence mode to take into account the influence of deformation condition and construction techniques of the tunnel.