褶曲构造影响区内工作面开采诱冲机理及其防治研究

Research on the mechanism and prevention of mining induced erosion in the working face affected by fold structures

针对褶曲构造影响区内不同工作面的倾角变化所引起的矿压显现特征多变性问题,以宝积山煤矿七采区为工程背景,采用现场调研、理论分析、数值模拟和现场工业性试验相结合的方法,对倾角变化煤层内不同工作面开采期间动静载荷进行了研究。结果表明:①煤岩组合系统刚度值大于0的累积声发射(AE)能量较煤岩组合系统刚度值小于0的累积AE能量小,说明煤岩组合系统刚度值小于0时更易累积AE能量,且在煤岩组合系统刚度值小于0时,其绝对值越大越能够积聚更高的AE能量。②随着煤层倾角递增,沿空巷道实体煤侧内集中静载荷降低,煤柱侧内集中静载荷增高,高位厚硬关键层发生破断所需悬顶段更长。③煤层倾角较小时,动静载叠加作用下沿空巷道两帮内煤岩组合系统极易诱发动态破坏II型冲击地压。煤层倾角较大时,高集中静载作用下沿空巷道煤柱侧内煤岩组合系统极易诱发静态破坏型或动态破坏I型冲击地压。④705综放工作面开采期间沿空巷道煤柱侧极易诱发静态破坏型或动态破坏I型冲击地压,对其实施防冲措施后的电磁辐射值降幅高达67.3%,煤岩组合系统不易诱发冲击地压。

The changes in dip angles of different working faces in the area affected by folding structures cause the variability of mining pressure features.In order to solve the above problem,with the seventh mining area of Baojishan Coal Mine as the engineering background,a combination of on-site research,theoretical analysis,numerical simulation,and on-site industrial experiments is used.The dynamic and static loads during mining of different working faces in coal seams with varying dip angles are studied.The results indicate the following points.The accumulated acoustic emission(AE)energy of the coal rock composite system with a stiffness value greater than O is smaller than that of the coal rock composite system with a stiffness value less than 0.This indicates that when the stiffness value of the coal rock composite system is less than O,AE energy is more likely to accumulate.When the stiffness value of the coal rock composite system is less than O,the larger its absolute value,the higher the AE energy can be accumulated.②As the dip angle of the coal seam increases,the concentrated static load inside the solid coal side of the goaf roadway decreases,and the concentrated static load inside the coal pillar side increases.The hanging top section required for the cracking of the high and thick hard key layer is longer.③When the dip angle of the coal seam is small,the combined system of coal and rock in the two sides of the goaf roadway is prone to inducing dynamic failure type II rock burst under the combined action of dynamic and static loads.When the dip angle of the coal seam is large,the coal rock combination system inside the coal pillar side of the goaf roadway is prone to inducing static or dynamic failure type I rock burst under high concentrated static load.@During the mining period of the 705 fully mechanized top coal caving face,the coal pillar side of the goaf roadway is prone to inducing static or dynamic failure type I rock burst.After implementing anti erosion measures,the electromagnetic radiation value decreases by up to 67.3%。The coal rock combination system is not easy to induce rock burst.