煤炭工程 ›› 2024, Vol. 56 ›› Issue (9): 105-111.doi: 10.11799/ce202409017

• 生产技术 • 上一篇    下一篇

近直立煤层顶底板爆破防冲方法数值模拟研究

蒋新军,苗春光,胡旭聪,钟涛平,刘旭东,李振雷   

  1. 1. 国家能源集团新疆能源有限责任公司,新疆 乌鲁木齐 830027

    2. 北京科技大学 土木与资源工程学院,北京 100083

  • 收稿日期:2024-03-13 修回日期:2024-06-27 出版日期:2023-09-20 发布日期:2025-01-08
  • 通讯作者: 胡旭聪 E-mail:371898277@qq.com

Numerical simulation on roof and floor blasting rock burst prevention for nearly vertical coal seams#br#

  • Received:2024-03-13 Revised:2024-06-27 Online:2023-09-20 Published:2025-01-08

摘要:

近直立煤层由于顶底板的挤压撬动作用,其冲击地压防治难度较大,本研究以乌东煤矿南采区为工程背景,进行了近直立煤层顶底板岩体爆破卸压防冲方法的研究。通过案例分析、数值模拟和现场验证等方法,分析了近直立煤层发生冲击地压期间采取的深孔爆破措施卸压防冲效果。尽管深孔爆破能够减少顶底板的压撬作用产生的动载,但对工作面近场围岩的弱化及静载的降低效果不佳。针对这些不足,提出了深浅孔爆破卸压防冲方法,结合深孔与浅孔爆破,既弱化了压撬作用导致的动载又有效弱化工作面围岩并降低静载集中,具体方法包括深浅孔交替爆破和深浅孔同时爆破。相比于单一深孔爆破,这两种方法都能进一步降低巷道围岩水平应力峰值。深浅孔同时爆破的防冲效果优于交替爆破,但工程成本更高。在乌东煤矿南采区应用了深浅孔交替爆破防冲。微震监测结果显示,相较于深孔爆破实施深浅孔爆破后,104J以上大能量事件的发生率从9.3%降至0.2%,微震能量以“低频高能”转变为“高频低能”平稳释放,有效降低了冲击地压危险。研究成果可为近直立煤层冲击地压的防治工作提供重要支撑。

关键词: 近直立煤层, 冲击地压, 爆破卸压, 数值模拟

Abstract:

Due to the compressive and prying actions of the roof and floor, preventing rock bursts in near vertical coal seams presents considerable challenges. This study focuses on the Wudong Coal Mine's southern mining area, investigating the blasting pressure relief methods for the roof and floor rock bodies in near-vertical coal seams. Using case studies, numerical simulations, and onsite validations, this research analyzed the effectiveness of deep-hole blasting measures during rock burst occurrences in near-vertical coal seams. Although deep-hole blasting reduces the dynamic loads caused by the compressive and prying actions of the roof and floor, it is less effective in weakening the nearby rock mass at the working face and reducing static loads. To address these shortcomings, this study introduces a combined deep and shallow hole blasting method that mitigates the dynamic loads from prying actions, effectively weakens the rock mass at the working face, and reduces the concentration of static loads. The techniques include alternating deep and shallow hole blasting and simultaneous deep and shallow hole blasting. Compared to single deep-hole blasting, both methods further reduce the peak horizontal stress in the surrounding rock of the roadway. The simultaneous deep and shallow hole blasting shows better rock burst prevention effects than alternating blasting but at a higher engineering cost. In the southern mining area of Wudong Coal Mine, alternating deep and shallow hole blasting has been applied. Microseismic monitoring results indicate that, compared to deep-hole blasting alone, the implementation of combined deep and shallow-hole blasting significantly reduced the occurrence of high-energy events (greater than 104J) from 9.3% to 0.2% and shifted the microseismic energy from "low-frequency high-energy" to "high-frequency low-energy," effectively mitigating the risk of rock bursts. These findings provide significant support for preventing rock bursts in near vertical coal seams.

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