长平煤业3号煤层冲击倾向性测试与危险性评价分析OA

Rock burst accidents in coal mines frequently occurred in high in-situ stress areas of hard and brittle coal-rock masses and coal seams with a burial depth exceeding 400 m.With severe hazards,such accidents were caused,bringing huge economic losses and casualties to coal mines.The mining depth of No.3 coal seam in Changping Coal Industry was more than 400 m,which met the critical mining depth standard for rock burst-prone coal mines in China.To prevent the occurrence of rock burst accidents in No.3 coal seam,rock burst tendency tests and risk assessment analyses were carried out in this study.The test results were presented as follows:the average values of dynamic failure time,elastic energy index,burst energy index and uniaxial compressive strength of No.3 coal seam in Changping Coal Industry were determined to be 2 312 ms,3.06,1.94 and 6.55 MPa,respectively.Through comprehensive judgment,No.3 coal seam in Changping Coal Industry was identified as non-rock burst tendency.The bending energy indexes of roof and floor strata of No.3 coal seam were calculated as 11.867 kJ and 7.174 kJ respectively,both of which were less than 15 kJ,and the roof and floor strata were classified as non-rock burst tendency.In accordance with the comprehensive index method of coal seam geological factors and mining technical factors,the rock burst risk level of No.3 coal seam in Changping Coal Industry was evaluated as non-rock burst risk.The relevant test data were provided in this research,which can supply basic parameters and decision-making bases for mine mining and rock burst prevention and control,and the safe and efficient production of the mine was guaranteed.