Study On The Mutation Rupture Of Karst Tunnel And Disaster Prevention

In Karst area, due to its special geological structure, water inrush and mud geology disaster phenomenon taking place most easily in the process of tunnel construction, it has become a bottleneck restricting of the fast tunnel construction. According to this, on the basic of karst tunnel geological disasters, this paper studied on the tunnel disaster and disaster prevention of karst area, get the following conclusions by using the methods of theoretical analysis and numerical simulation:(1)Summary of karst forming conditions and classifications, points out its developmental control factors; It elaborated that karst easily lead to the tunnel collapse, karst water inrush and sudden mud unfavored geological disasters.(2)Based on the objective reality that karst water bursting disaster is formed for a long time and it has a huge energy release, the process is divided into the energy accumulation and rapid instability. Through the mechanics description, it gets the expression of the influence of underground Water on the Strength of fissure rock mass. Based on the Bernoulli equation, it reveals that karst water pressure has hybrid control effect to water-inrush. The theory of fracture mechanics used in crack growth under the water corrosion.The crack propagation pattern is divided into tension-shear failure and compression-shear failure. It calculates the formula that the critical water pressure causes crack growth.(3)Research on the mechanics for water burst catastrophe in a karst tunnel, its analysis was focused on the mechanism of the outburst prevention Structure mutation rupture and karst tunnel instability caused by deformation of structure plane in rock mass. Ground on the energy conservation principle, the cusp catastrophe model of perilous rock is established, and the critical exponent to distinguish the dynamic instability of deformation of structure and karst tunnel is gained. The equilibrium surface shows a jump from one state to another of the dynamic systerm. Through the analysis of the control parameters, it shows the control effects of creep control factor to the evolution speed of karst tunnel weak structure plan.(4) It mainly discusses the geological method, pilot drift method, geological radar and infrared detection method of tunnel geological forecast technology. Through the theoretical analysis and the practical application, it puts forward some effects of all kinds of detection methods should be paid attention to in the construction and application. Study respectively on small and large caves filled mud karst treatment technology, it puts forward corresponding disposal measures.Based on the numerical model establishedby MIDAS/GTS, the simulation results better demonstrate the rationality of the treatment technology.