采区煤柱区域微震规律分析及冲击地压防治技术
Analysis on regional microseism law of coal pillar in mining block and prevention and control technology of mine pressure bum p
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摘要: 分析采区煤柱区域微震活动规律,为冲击地压防治提供依据。以张小楼矿井-1 025 m西一下山采区为例,建立微震频次、能量集中比,分析了采区煤柱区域与全采区微震空间活动性,采用微震事件空间分布分析了工作面回采动态扰动速度和范围以及采区煤柱核心区域的微震分布及大能量微震事件演化过程。结果表明:微震事件在采区煤柱区域存在集中分布,煤柱区域微震频次集中比为3.25,微震能量集中比为3.37;工作面回采速度与采区煤柱微震频次、能量成正相关;工作面超前影响距离平均为166 m,最大为228 m,采空区滞后影响距离平均为90 m,最大为125 m;微震首先出现在远离煤柱核心区的强剪切带,随着工作面的回采,当核心区域的应力达到支承极限时,大能量微震事件发生,冲击危险性增加。通过实施消能限冲技术,成功避免了动力灾害,实现安全开采。Abstract: An analysis was conducted on the regional microseism activity law of the coal pillar in the mining block and could provide the basis to prevent and control the mine pressure bump.Based on the-1 025 m West First Downill Mining Block in Zhangxiaolou Mine as a case,the microseism frequency rate and energy concentration ratio were established and the microseism space actvity in the coal illar zone of the mining blok and the whole mining block was analyzed. The space distribution of the microseism events was applied to analyze the mining dynanic disturbance speed and scope of the coal mining face as well as the microseism distribution and the large energy microseism event evolution process ofthe coal pillar key region in the mining block. The results showed that the microseism events were concentrated distributed existed in the coal plar region of the mining block. The microseism frequency rate concentration ratio in the coal pilar region was 3.25 and the microseism energy concentration ratio was 3.37.The mining speed of the coal mining face would have a posiive relationship to the microseism frequency rate and energy of the coal pillar in the mining block. The advance influence distance of the coal mining face was 166 m in average and the max infuence distance was 228 m. The hysteresis infuence distance in the mining goaf was 90 m in average and the max hysteresis infuence distance was 125m.T'he microseism was firstly occurred in the strong shearing zone with a far distance to the calpillar core zone. With the mining operation of the coal mining face,when the stress of the core region reached the support limithe large energy microseism event would be occurred and the mine pressure bump danger would be increased. with the practices of the energy dissipation and bump buffer technology,the dynamic disaster was successfully eliminated and a safety mining was realized.