近距离煤层开采围岩破坏及支护阻力研究

Study on Failure of Surrounding Rock and Support Resistance in Close Distance Coal Seam

针对近距离煤层开采围岩破坏所引起的工作面冒顶、漏矸问题,以甘肃某矿采矿地质条件为背景,通过理论分析采高和应力集中系数对底板破坏深度的影响关系,得出当采高大于6 m时,应力集中系数大于3时,对底板破坏深度影响程度显著。通过数值模拟得到16#煤层开采超前支承压力集中系数约3.75,覆岩破坏高度约30 m,结合理论分析结果得出底板破坏深度约4.23 m。17#煤层顶板受16#煤层采动影响产生破坏,液压支架承担17#煤层与16#煤层层间岩体与16#煤层采空区垮落岩层的载荷,确定液压支架支护强度应不小于0.61 MPa,以保证17#煤层工作面安全高效开采。

For close distance coal seam coalface roof falling and collapsed rock caused by damage of surrounding rock,taking the mining geological conditions of a mine in Gansu province as the background,through the theoretical analysis the influence of mining height and stress concentration coefficient on floor failure depth,it is concluded that when mining height is greater than 6 m,the stress concentration coefficient is more than 3,significant influence on floor failure depth.Through numerical simulation,the concentration coefficient of advanced abutment pressure of No.16 coal seam is about3.75,the failure height of overburden is about 30 m,and the floor failure depth is about 4.23 m combined with theoretical analysis results.The roof of No.17 coal seam is damaged by the mining effect of No.16 coal seam.The hydraulic support bears the load of rock mass between No.17 coal seam and No.16 coal seam and the load of caved rock layer of the goaf of No.16 coal seam.The support strength of the hydraulic support should be determined not less than 0.61 MPa to ensure the safe and efficient mining of the coalface of No.17 coal seam.