Study On Deformation Failure Mechanism And Double “Shell” Reinforcement In Deep Soft-Rock Roadway

With the continuous improvement of the mechanized production of the mine, the scale and quantity of the underground engineering is also gradually enlarged, and the deep construction has become the inevitable choice of the underground engineering activities. Geological conditions of deep roadway and mining field are very complex, high stress, high temperature and soft rock control problem is becoming more and more important. The study of deep soft rock roadway deformation failure mechanism and the deformation of the surrounding rock characteristics and stability control of roadway technology of deep mining has important significance. Combining the deformation characteristic of high stress roadway of Taoer mine in Jizhong energy Handan Mining Group, according to the domestic and foreign in deep soft rock roadway of progress, surrounding rock deformation and failure characteristics of soft-roadway with different support is analyzed by theory analysis and simulation. Support bearing characteristics of double “shell” with different parameters is analyzed by contrast. The main research results as follows:(1) Based on the visco-elastic analysis of the model of Burgers on deep high-stress soft rock roadways, the expressions of surface displacement and displacement rate were calculated; at the same time, the curve of radius variation on displacement and velocity of surrounding rock under different lateral pressure coefficients were obtained. Based on the structure model, the deformation and failure characters under different circumstances was analyzed using numerical simulation method. The evolution rule of the deformation, stress, plastic and crush zone along with time was got.(2) In the basis of deep soft rock roadway deformation characteristics and mechanism, reinforcing concept of double “shell” was put forward; yielding shell with pretensioned anchor and grouting was to improve the shallow rock structure, set aside enough expansion energy of deformation time; reinforcement stress of the shell barrier is to make further destruction of pressure shell, which is sure to let yielding shell own enough bearing capacity of the roadway and long-term stability. In order to ensure the capacity of yielding shell, the effect of yielding shell with different parameters on stability of surrounding rock supporting were analyzed by FLAC3 D.(3) combined with coal and rock failure mechanism and mechanics principle, the grouting reinforcement mechanism of broken coal and rock is analyzed. Furthermore,the influence characteristic of grouting on the residual strength of grouting in different media were gotten by uniaxial compression test.(4) Failure process partition of surrounding rock instate was divided into wedge failure zone、second failure zone and sliding instability zone by CM60/10 plane strain test-bed. The characteristics of deformation and failure of surrounding rock mass of tunnel under different support parameters and its effect on the bearing characteristics of double shell and solid are obtained.(5) The relationship between grout strength parameters and strain were determined by numerical inversion and finally implanted in numerical calculation model. Inner and outer stress distribution, peak stress shifting law and bearing capacity of double “shell” with different parameters were analyzed by numerical calculation. The effect law of strength and thickness to combined supporting arch bearing capacity and outer surrounding rock stability was obtained.