Research on the law of underground pressure accumulation of complete roof in deep mining coal seam by centrifuge test

Based on domestic and foreign documents concerning this subject,the conventional similar materials simulation test can not simulate the original conditions and the mechanical environment in fact.Taking the geotechnical conditions of the first mining area in Zhaolou Coal Mine as geological background,the engineering geology model was set up.The laws of underground pressure accumulation on direct roof and main roof and coal pillar were drawn by centrifuge test.The results show that pressure variations of coal pillar and direct roof are basic synchrony,the degree of the variation of coal pillar pressure in front of working face is less than back,there are significant differences in coming pressure of time,pressure accumulation strength and loading stress case between the main roof and direct roof.Dynamic variations of the overlying strata pressure are simulated by applying centrifugal load in centrifuge,and the variations of pressure in coal pillar and roof strata are closer to the actual conditions.