孤岛面开采强矿震异常区的被动声波探测技术及应用

Seismic hazard assessment in complex island coalface by computed tomography

针对鲍店煤矿103上05孤岛面综放开采面临的高应力集中与强矿震威胁,论文在分析声波波速与加载载荷的关系基础上,建立了基于矿震被动声波探测的孤岛面开采矿震异常区评价方法,提出了采用P波波速异常与波速梯度异常2个指标进行采动应力集中程度的评价,并给出了判别标准,最后开展了现场实践。研究表明:P波波速与应力场具有正相关特性,103上05孤岛工作面临近小采空区侧常出现高波速与高波速梯度异常区,与后续开采阶段的强矿震异常区基本重合。实践证明该方法能够对孤岛面开采强矿震危险性与危险区域做出有效动态评价,强矿震活动的预警准确率较高。矿震被动声波探测技术提升了煤矿强矿震、冲击矿压等煤岩动力灾害的微震识别水平。

According to the high mining stress and seismic hazard risk in excavation operation of 10305 Island Coalface in Baodian coal mine, the relation between P-wave velocity and stress was analyzed, and the seismic hazard assessment method by using passive computed tomography in 10305 Island Coalface was established. Meanwhile, the indexes of P-wave velocity anomaly and velocity gradient anomaly were proposed to evaluate the stress concentration or seismic hazard zones, and the discrimination standards were also constructed. Finally, the assessment method was applied in 10305 Island Coalface. The results show that P-wave velocity and stress presents characteristics of positive correlation. The high velocity anomalies and velocity gradient anomalies are always located in the regions adjacent to the narrow goafing side of 10305 Island Coalface, which are basically similar to the anomaly areas of seismic hazards. The tomography detection practices show that it is feasible for seismic hazard assessment and anomaly region division during island coalface mining, and the hazard assessment accuracy is high. Thus, the passive computed tomography can improve the monitoring and pre-warning level for seismic hazards in underground mining.