The Model Test And Numerical Simulation Research Of Excavation In Deep Tunnel With Soft Rock

Deformation has obvious time effect and space effect of surrounding rock in deep underground engineering. It is mostly caused by the reasons that surrounding rock broken seriously under high stress, continuous creeping of hard rock and soft rock and long term strength degradation of rock. The outstanding characteristics of its deformation and destruction are nonlinear, asymmetry, rheological property and large deformation. Therefore, this thesis will be through of three kinds of technical means, that the mechanism analysis, model test and numerical simulation analysis, to carry out the study on stability of deep tunnel.Through the early development and testing of similar material, determine the suitable for the mixing ratio of similar materials, preparation of similar material in accordance with research content. The proportionality constant of elastic modulus, poisson’s ratio and compressive strength of each rock formations in the model test, is determined by bulk density and geometric similarity ratio. To achieve similar test requirement, research on rock mechanics performance test of model material and the layers of rock similar material gradation relationships, especially for soft rock similar material gradation relationships.Based on the preparation of similar material, to discuss the effects of the thickness of soft layer, section shape, the size of ground stress, the single tunnel and double tunnels and the location of the soft layer, carries on the model test. Exploring the most unfavorable factors, and then put forward the optimization design of tunnel excavation construction.This thesis will focus on deep engineering and related geological mechanics conditions, through the analysis of engineering geological structures and ground stress distribution, establish deep underground tunnel analysis model. By means of numerical simulation software FLAC3D, the thesis carried out numerical simulation of tunnel excavation and creep behavior. The results are reference to build early warning and disposal model of the actual project, and give a reasonable and reliable supporting schemes and suggestions.