Finite element analyses of Wanjiazhai water transmission tunnel excavation and service

摘要

This paper is devoted to the nonlinear stress and strain analysis of tunneling and working conditions of Wanjiazhai Division Project No.7 Tunnel in Shanxi province of China. The initial geological stress of loess was simulated by grading fill; the theory of unloading proposed by Duncan and boundary stress of elasticity were used to calculate the excavation of the tunnel; Goodman joint elements were applied to simulate the joints of the liners; both loading and unloading tests have been performed to determine the parameters of Duncan-Chang's model and the calculated results were compared; Terzaghi' s theory on loosening earth pressure was applied. Many working conditions were analyzed and some reasonable results were obtained. Based on the analyses, reparative measures were proposed and completed. The tunnel has functioned well since October, 2001.