Mechanics Mechanism And Numerical Simulation Of Mud Water Bursting In Karst Tunnel

With the rapid development of transportation industry in our country,tunnel and underground engineering problems more and more challenging.Especially in the construction of underground engineering and tunnel through karst area of the process,often encounter scale anging from sudden mud water inrush,collapse and other geological disasters,will cause serious damage to the construction safety and the surrounding environment,which restricts the development of tunnel and underground engineering.The bursting of mud and water in the karst tunnel is mainly due to the filling type karst cave of filler in the construction process of the impact on the surrounding rock,erosion and destruction,and make the surrounding rock instability,resulting in karst tunnel mud water inrush disaster.Therefore,the key problems such as karst tunnel mud water inrush mechanism research,has great value of engineering application,this paper based on Liuyuetian tunnel yongji expressway in hunan province,by collecting data and laboratory test,theoretical study and numerical simulation methods,sudden mud water inrush mechanism research on karst tunnel,tunnel by mud water inrush mechanics model is set up,and through the analysis indicates that the factors affecting tunnel sudden water inrush mud,using the finite element software Midas-NX to simulate the influence of the compaction on the stability of the rock strata under different factors.The main work of this paper:(1)Relying on the hunan yongji high-speed Liuyuetian tunnel,through detailed geological investigation,organization of tunnel site area landform,stratum lithology,geological structure,hydrogeology,engineering geological conditions,such as the analysis of karst tunnel mud water inrush mechanism.(2)Field Liuyuetian shallow buried tunnel in the cross section of the film clip a field monitoring data were analyzed,and the simple introduction of field monitoring for tunnel construction guidance,field for Liuyuetian tunnel gushing fillings do indoor test,study its permeability and shear strength.(3)Based on catastrophe theory,using the cusp catastrophic model simplified karst tunnels filler of rock-salt cavity for the circular plate and beam mechanical model,the analysis of two mechanical model of tunnel and filler rock-salt cavity between the influence factors of rock instability.(4)Based on practical engineering geological and hydrological conditions,the design data,a three-dimensional numerical model is set up,on this basis,simulation of different parameters on the stability of the formation between solution cavity and tunnel surrounding rock strata,the influence of the analysis under the condition of different parameters of surrounding rock of the tunnel and the filler of rock-salt cavity between strata stress,displacement and plastic zone.According to the stress,displacement and plastic zone change to judge whether the rock instability.(5)In a three-dimensional model on the analysis results of the four parameters of surrounding rock of a two-dimensional model is established and simulated different hole diameter,cavity filling cavity filling with different distance from tunnel roof and ground water level on tunnel with padding,the influence of rock-salt cavity between strata analysis in different hole diameter,diameter ratio and underground water level under the condition of tunnel and filler of rock-salt cavity between strata stress,displacement and plastic zone.According to the change of plastic zone and extension situation how to judge the rock failure.