Study On The Semi-analytical Solution Of Ground Deformation Induced By Tunnel Construction

When constructing underground structures such as subway in the urban, we must premise the normal use of the surface buildings, if the settlement and deformation of the ground is too large it will cause the settlements or cracks of the roads or buildings. It will have serious implications for their safe application. To reduce the adverse effects of surrounding environment induced by construction of the subway, we must effectively to predict the ground movement. The main content of the thesis is as follows:1. First summarizes the current calculation methods and theories of ground movement induced by constructing subway at home and abroad. Based on the Mindlin displacement solution in elastic half-space, deduce the semi-analytical solution of ground movement induced by tunnel constructing. And use the derived semi-analytical solution applies to the engineering examples of single and double tunnels, analyzed and verified the reasonable of this method.2. Applying the derived semi-analytical solution based on the Mindlin displacement solution in elastic half-space, analyzing the quantitative law of ground movement induced by tunnel construction at different diameter,different stress releasing coefficient and different soil compression modulus influence factors.3. Based on the Mindlin displacement solution in elastic half-space, derived the semi-analytical solution in shield tunnel construction considering the addictive thrust on the tunnel face,lack thrust on the tunnel face,the fiction force to the surrounding soil and the soil excavation unloading, etc. And analysis of these factors on the impact of shield tunnel construction.4. Through analyzing the addictive thrust on the tunnel face, we found that the front soil uplift and the rear soil settlement, if the tunnel depth is not too deeper then the addictive thrust will have a obvious impact of the deformation of the surface. When the thrust is less than front the soil pressure, it will cause the settlement of the front soil. The fiction force to the surrounding soil cause the front soil uplift and the rear soil settlement.