The Effect Of Fissure Under Ground Water On The Subway Of Xi'an

In the district of Xi'an, there has been found disaster of ground fissures and subsidence of ground seriously. There may be large-area subsidence of ground surface before the excavation of tunnel if we adopt the drainage construction method in weak stratum which is full of water. Therefore the primary contents of this thesis are researching non-drainage construction method which may restrict the water discharge in excavation of tunnel to reduce the consolidation settlement of stratum. Moreover, the under fissure and water is considered to analysis stress and strain after the subway is been used. This can afford some safety for the use of subway.This thesis adopts the ADINA as compute tool for engineering mechanics computation. Thesis considers the effect of fluid-mechanical interaction and utilize the strong power of the fluid-mechanical module in ADINA to built the fluid-mechanical-settlement models of subway tunnel which is constructed in drained, non-drained conditions and used in earthquake, ground warter changed respectively. In this paper, a nonlinear FEM model of RC shield tunneling lining and surrounding rock of tunnel are proposed to deal with the simulation of Xi'an Underground. The nonlinear FEM code ADINA is used to analyze the stress and strain behavior of lining structure which is subjected to the covered soil and the applied surface loads. Then the stress, strain, structural displacements and crack distribution are illustrated in this paper. After analysising the figures, the shield tunneling lining can be designed. Thesis simulates the processes of seepage, mechanical, settlement in the same time and studies on the relationship between water discharge and displacement of ground surface. Thesis contrasts the different subsidence in three drainage conditions and then finds that preventing or reducing the loss of ground water in stratum are effective methods to restrict subsidence of ground surface. Additionnally, since the subwaycross ground fissures, it is important for us to consider the effect of earthquake and underground water and find an effective and reasonable way to solve this problem.