Numerical Simulation Study On The Subsidence Of Ground Cause By Construction Subway In Stratum Which Contain Aboundant Water

Drainage method is the most universal techniques in the subway construction in our country. This method may provide a favorable condition which may insure the process of subway tunnel construction against water. Along with the consciousness of environmental protection are more important in people's mind, we realize that the drainage method may do harm to environment seriously. For example. It may induce the large-area subsidence of ground surface and the dehiscence which is due to the non-uniform subsidence of buildings and road surface. 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, especially in the south of our country. 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.This thesis adopts the FLAC^3D as compute tool which is a three dimensional explicit finite-difference program for engineering mechanics computation. Thesis consider the effect of fluid-mechanical interaction and utilize the strong power of the fluid-mechanical module in FLAC^3D to built the fluid-mechanical-settlement models of subway tunnel which is constructed in drained, non-drained and dynamic drained conditions respectively. 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 discovers that the dehydration of stratum dominates the subsidence of ground surface, therefore to prevent or reduce the loss of ground water in stratum are effective methods to restrict subsidence of ground surface.