Multi-Field Monitoring And Numerical Simulation Analysis Of Mining Stress-Seepage-Fracture In Floor

With the continuous development of coal resources,Shendong mining area has gradually entered a relatively deep stage,and the water hazard of floor limestone is becoming increasingly serious.The 81307 working face of Baode Coal Mine in Shendong is selected as the typical research face.The dynamic monitoring method of mining stress field-fissure field-seepage field is established by means of borehole stress sensor,mining seepage pressure sensor and panoramic borehole peeper.Then the evolution law of multi-fields of coal seam floor mining along with the advancing of working face is analyzed and obtained by using FLAC3 D numerical simulation software.The fluid-solid coupling of the floor is simulated numerically,and the simulation results are compared with the field monitoring results.Through the research in this paper,the change rule of stress,crack and seepage in the process of floor mining with the advancing of working face is obtained systematically,which provides technical guarantee for the prevention and control of floor water hazard in Baode Coal Mine.Through the research of this paper,the main achievements are as follows:(1)Field experiments and numerical simulation studies show that under mining stress,the stress at the monitoring point of the floor increases first,then decreases and tends to be stable.The calculation and numerical simulation of the monitoring data show that the plastic failure depth of the floor rock is about 20-25 m.(2)Under the action of mining stress,with the continuous advance of the working face,the floor fracture depth gradually increases,and when the working face advances to the top of the monitoring point,the floor cracks fully develop.(3)Through on-site monitoring and numerical simulation analysis,it is concluded that with the advance of work,pore water seepage pressure of floor rock increases gradually as the fracture surface of floor rock increases.When the working face advances to the upper part of monitoring point,pore water seepage pressure reaches its peak value,then decreases rapidly,and then gradually restores stability,which is related to the mining damage caused by falling gangue in goaf.Fracture compaction is related.(4)The results of numerical simulation and field physical monitoring show that the stress field-fissure field-seepage field of mining floor has obvious causal coupling relationship.The results of field physical monitoring are similar to those of numericalsimulation.The research results can further understand the evolution and coupling law of stress-fissure-seepage field of mining floor with the advancing of working Figure [32] table[4] reference [76]...