Research On The Structural Stability Of The Surrounding Rock About The Wu Shen Expressway Xiao Fangshan Tunnel

This article rely on the Xiaofangshan tunnel of Wu-shen expressway, uses the stability of the highway tunnel surrounding rock structure analysis as the main lines, in order to optimize and enhance the design and safety construction.We use the method of quantitative evaluation, qualitative evaluation, overall evaluation and partial evaluation, to carry out research on the stability of surrounding rock in the Xiaofangshan tunnel. Main content has the following several points:â‘  The load is an important index of the structure stability, this paper will start with the calculation of small spacing tunnel, combine the calculation principle and formula of load in shallow buried tunnel and the specification of the bias tunnel.We will carry out a series of calculation method after the analysis of the shallowand bias buried tunnel. And then give out the formula of the small spacing tunnel in shallow cover load case.â‘¡ The formula derivation of the small spacing and shallow bias buried tunnel, we turn into the numerical simulation analysis for small spacing shallow bias section of the construction of the Xiaofanshan highway tunnel. The whole process of construction of small mountain tunnel is simulated by Tongji Shuguang software. Take the first right hole after the left hole and the right hole after the left hole step method construction, we obtained the stress and deformation by these two kinds of construction sequence of surrounding rock, this gives a great reference value for the optimization design and the safety constructiong of Xiao Fangshan, specially making a contribution to the field of construction order and the construction safety precautions. Then, this paper conducted numerical simulation of shallow bias section and also get the displacemen of surrounding rock and supporting structure.Through the comparison with the same bias sections, twe get the effect of the bias on tunnel surrounding rock.â‘¢ By two different construction method we carry out numerical simulation of deep buried section IV rock, obtained the stress and displacement of two kinds of construction methods of surrounding rock and supporting structure ineach construction, in order to make the theory support to guide and assist the construction.â‘£ We discussed the influence of stress releasing coefficient and two liner stresses. Through two differentlining stress release coefficient of the internal force and deformation, the deformation and internal force of lining was two and the relationship between the stress releasing coefficients. This makes the reference for the site construction of time node, and can also give some reference significance for similar engineering.