Study On Deformation And Failure Of Overlying Rock Mass Of Tunnel In Chongqing

The deformation and failure of rock inclined rock tunnel tunnel is a complex process,the overlying rock mass structure will be affected by many factors,including the influence of natural geological factors,but also in the influence of human factors in design and construction,various factors will inevitably affect each other to produce.In the actual geological environment,all kinds of deformation and failure of tunnel excavation are the products under the influence of various factors.Chongqing is a mountainous area,the construction of the tunnel is very important in the construction of urban traffic,how to ensure its safety and stability is a problem that all parties must consider.On the basis of sedimentary rocks in Chongqing area,the structural form of overlying strata is a very common structural form.Because of the characteristics of the layered characteristics and the structure of the decision of the stress after the deformation and failure of the particularity of the research on this problem,many domestic and foreign scholars have always maintained a high degree of enthusiasm.Based on this background,the deformation and failure of overlying rock mass are studied in this paper:(1)The system structure of tunnel surrounding rock system is expounded,and then classify accurately and effectively according to the structure of rock mass,then according to different classification results,the deformation and failure of each type of structure explanation.In the overall evaluation,the structural types and failure characteristics of the gently inclined overlying rock mass are analyzed and studied.(2)The relationship and characteristics of the tunnel structure and the overlying rock,the tunnel overlying layered rock as rock beam structure,as the elastic foundation of the tunnel structure,combined with mechanics and calculus theory using Winkler elastic foundation theory,solving the uniform load deformation formula for bending of single and double rock beam structure the use of analytical expressions for the upper rock beam structure deflection value.(3)Using the finite element analysis software,according to the Chongqing area of gently inclined rock tunnel overburden deformation and failure of specific reasons to produce effects,such as slow tilt angle,the thickness of rock,the original stress,design of strata structure location relation and tunnel in the specified height and small span to carry out numerical simulation analysis,calculation of different extraction the controlling factors of the results were analyzed to determine the importance of each influence factor.(4)The theoretical deformation value of the overlying rock mass is calculated by using the analytical formula of rock beam deflection.The results of theory and numerical analysis,according to the results of different factors under the gap value of the corresponding correction,finally get the deflection of single and double rock beam deformation equation under different factors,and then the theoretical calculation and field data for comparative analysis,demonstration of rock beam deflection formula of the accuracy and feasibility of using in the practical engineering.In this paper,some conclusions can be used to predict the deformation and damage caused by tunnel construction in certain geological environment.