Study On Deformation Of Surrounding Rock And Mechanical Characteristics Of Supporting Structure Of Unbalanced Pressure Tunnel Intersection

In recent years,with the rapid development of China’s national economy,the construction of tunnel engineering changes with each passing day.In the construction of tunnel engineering in complex mountainous areas,the phenomenon of bias caused by geological structure is more and more common.Based on the summary of the existing research results,this paper uses the finite element numerical method to study the stability of the surrounding rock and the mechanical characteristics of the initial support structure at the intersection of the main tunnel and the auxiliary tunnel(hereinafter referred to as the intersection).The main research contents and research results are as follows:1.By analyzing the supporting scheme of the surrounding rock of the bias pressure tunnel intersection,the mechanical mechanism,failure mode and deformation characteristics of the tunnel instability are analyzed,and the influence of various factors on the deformation of the surrounding rock of the tunnel is studied.2.Based on the physical and mechanical parameters of the actual engineering stratum,a three-dimensional numerical model of the surrounding rock at the intersection of the unsymmetrical pressure tunnel considering the strength and occurrence of the surrounding rock is established.3.By using the numerical simulation method,the dynamic simulation,numerical calculation and result analysis of the surrounding rock structure under the condition of different dip angle and different spacing are carried out,and the stability of the surrounding rock and the mechanical characteristics of the initial support structure at the bias tunnel intersection under various working conditions are studied.The research results of this paper have been successfully used in the construction of Chongqing Fenshuiling tunnel,which can provide reference for the design and construction of similar projects.