Numerical simulation method for stope underground pressure in whole process of longwall mining

According to the large deviation of simulation results of longwall mining strata behaviors by the traditional numerical simulation method,based on the analysis of the whole process of longwall mining,the plasticity theory,the damage softening constitutive model and the double yield constitutive model,a numerical simulation method for stope underground pressure in whole process of longwall mining is proposed. The theoretical basis of this method takes into account the physical process of damage softening of coal and rock mass,caving of roof,filling and pressure bearing in gob during mining,and numerical algorithm is developed by using FISH language of FLAC3D and can be realized nu- merically. This method is used to simulate the mining process of a certain face in Tongxin coal mine,the results are in good agreement with the field practice. The morphological characteristics of the monitored vertical displacement curve of the overburden can be used to effectively determine the distribution range and the dividing line of the three zones, and the pressure data of the monitored hydraulic support reflects the periodic weighting and the weighting interval. The research results provide a new idea and method for the numerical simulation of longwall mining strata pressure behav- ior law.