Study On The Laws Of Strata-pressure Behavior And The Stability Of The Coal Wall In Large Mining Height And Top Coal Caving Working Face In Tunliu Mine

Based on the Luan Tunliu mine, which is high gas and soft thick seam,the paper uses the methods of oretical analysis, numerical simulation and field test to study on the strata-pressure behavior and stability of the coal wall in working face of large mining height and top coal caving. On this basis, I suggest the way to enhance the stability of the coal wall in working face. With contrast to the similar condition top coal caving working face, the results show that the strata-pressure is more intensity and influence scope of advance support pressure is bigger and stress concentration factor is also bigger in working face of large mining height and top coal caving. So the difficulty maintenance stability of coal wall is also harder. And in the condition of Tunliu mine, the main production technologys that influence stability of the coal wall are the horizontal force of protect board and cutting altitude of the coal mining machine and protections intensity of hydraulic support and so on. In practical control the stability of the coal wall, coal slide and roof fall are two processes which affect mutually. When coal slide, it causes the non-supports space that between the support and the coal wall larger, which cause roof fall. And when the roof fall happened, the non-level restraint altitude of coal wall is larger, then intensify the coal slide. The protection intensity and cutting depth of coal mining machine influence the distortion and destruction of the top coal of end face directly, which affect the stability of coal wall by affect the top coal. On the other hand, the horizontal force of protect board and cutting altitude influence the distortion and destruction of the coal wall directly, which affect the stability of top coal by affect the coal wall. In addition, working face length and working face advancement speed and the angle of down or up dip mining are remarkable influence to the stability of the coal wall. In actual production process,we can decrease the cutting altitude and inprove the protections intensity and reduce the cutting depth of coal mining machine and so on to enhance stability of the coal wall large mining height and top coal caving working face.