Through The Rock Contact With The Surrounding Rock Of Tunnel Construction Stability And Deformation Study

There are mainly mountainous and hilly areas in southern China with topographic and geological conditions rather complex. The construction for highway tunnel encounters a number of complicated geological problems, and the tunnel rock contact zone is prone to geological disasters, under which engineering problems like how to ensure quality and reduce losses need to be solved.This paper studies Ban Jiangzi Tunnel of Chenzhou to Rucheng highway in Hunan province. According to the collection of the tunnel engineering geology reports, design drawings and the tunnel construction, as well as the dynamic monitoring of the construction on the spot, microscopic observation of indoor rock, and comparison between numerical simulation and field test results, the paper bases the analysis on geological features, deformation characteristics and the stability of tunnel surrounding rocks around the rock contact zone in the Ban Jiangzi tunnel. The paper also focuses on rock deformation characteristics when tunnelling through rock contact zone and optimizes research on support parameters.The main ideas are as follows:(1) Based on comprehensive analysis of document materials, the domestic and foreign research methods and development status of the deformation control of surrounding rocks when tunneling through rock contact zone are summarized, and the research ideas of the paper was determined;(2) Through indoor microscopic analysis of on-site rock samples, combined with field mapping of geological sketch profiles of rock contact zone, and the geological forecast results of the rock contact zone, the paper studies the gradual change feature analysis of tunnel surrounding rock in rock contact zone, and analyzes the influence of structural surface of rock contact zone to the tunnel stability and deformation of surrounding rock in Ban Jiangzi tunnel;(3) Considering the influence of gradual change feature of rock contact zone to the stability and deformation of tunnel surrounding rock, combined with field data analysis results, the numerical model was found by using discrete element analysis software UDEC to implement numerical simulation of two-dimensional elastic-plastic. The paper analyzes the impact of the stress from surrounding supporting structures and deformation rules, the rock contact zone to the stability and deformation of tunnel surrounding rocks in the construction process. By appllying to the field measurement and numerical simulation results, the paper also analyzes the supporting effect, and optimizes the supporting parameters.