Study On Stability Of Surrounding Rock Of Yingpanshan Tunnel In Fluid Solid Coupling State

Our country is a country with complex terrain and mountainous areas.In the construction of highways,most of them loop around mountains or cut slope deep digging.At the present stage,the linear requirement of tunnel engineering is gradually improving.So adverse geological conditions can not be avoided in the complex strata,such as fault broken zone,high crustal stress,Karst,etc.Strength of surrounding rock is one of the main factors influencing the stability of the constraints,especially the development of structural planes such as joints and fissures geological area rich water,construction of the tunnel are not just force field,seepage field,stress field and the existence of human activities,the instability and failure of tunnel constraints are more likely to happen,the water inrush caused by sudden,gas,such as rock burst accident of project.The casualties and economic losses caused by water and mud outburst are in the forefront of all kinds of tunnel geological disasters.China is one of the most serious countries of water damage in the world,especially Chengdu-Kunming railway water damage tunnel accounted for 93.5%.Therefore,it is of great significance to analyze the stability of the face of Yingpanshan tunnel under the condition of fluid-structure interaction.Based on the Yingpanshan tunnel project of Huaping to Lijiang Expressway,this paper uses the numerical simulation method to study the stability of the face of the tunnel under the condition of fluid-structure interaction.The research results of this paper are as follows:(1)Extensive collection of relevant literature and theoretical data analysis,tunnel excavation leads to the interaction and interaction between seepage field and stress field,including groundwater stress field redistribution through mechanical action,groundwater weakening effect on rock mass;And the influence of permeability of rock mass on seepage.(2)The numerical model calculation results of open seepage module and non-open seepage module are compared and analyzed.Based on the general situation of Yingpanshan tunnel,tunnel and geotechnical analysis software GTS NX is used to conduct numerical simulation,and two numerical models of fluid-structure coupling and non-fluid-structure coupling are established in the construction stage.The seepage field,displacement field and stress field of surrounding rock in the process of excavation of the face are compared and studied,and the related change rules are obtained.(3)by considering the fluid-structure coupling effect,the rich water fracture zone in the condition of fluid-structure interaction of surrounding rock stability,the factors of the stability of surrounding rock(tunnel buried depth,the initial water level)are studied,according to the influence of related factors,summed up the key parts of the stress field,plastic area move field,seepage field change law and increasing coefficient,provide a reference basis for related projects.