煤炭工程 ›› 2024, Vol. 56 ›› Issue (6): 21-27.doi: 10. 11799/ ce202406004

• 设计技术 • 上一篇    下一篇

上保护层开采下特厚突出煤层沿空巷道合理位置研究

任启寒   

  1. 1. 煤矿灾害防控全国重点实验室,重庆 400037 2. 中煤科工集团重庆研究院有限公司,重庆 400037
  • 收稿日期:2023-05-31 修回日期:2024-03-21 出版日期:2023-06-20 发布日期:2025-01-08
  • 通讯作者: 任启寒 E-mail:1439985797@qq.com

Research on the reasonable location of gob roadways in extra thick outburst coal seams under upper protective layer mining

  • Received:2023-05-31 Revised:2024-03-21 Online:2023-06-20 Published:2025-01-08

摘要:

基于上保护层开采下特厚煤层瓦斯地质条件,综合理论分析、数值模拟、工程实践等方法,对采空区侧向应力分布特征、突出危险性预测指标变化规律及沿空巷道合理位置进行了研究。结果表明:上保护层开采后裂隙岩体存在应力恢复效应,应力恢复后采空区侧向应力峰值会向采空区方向移进;根据采空区侧向不同距离下的煤体突出预测指标测试结果划分了充分卸压排放区、有效卸压排放区及危险区域,结合工程类比、数值模拟结果、隔绝采空区气体需要,确定了沿空煤柱留设宽度为5~7m;调整后巷道掘进期间突出预测指标及回风瓦斯浓度最大值分别为0.16mL/(g·min1/2)、0.22%,与未调整之前相比降幅分别达到66%、35.3%,保证了巷道安全掘进,验证了沿空煤柱留设的合理性。

关键词: 保护层开采 , 特厚煤层 , 突出危险 , 侧向应力 , 煤柱宽度

Abstract:

Based on the geological conditions of gas in the ultra-thick coal seam under the mining of the upper protective layer, comprehensive theoretical analysis, numerical simulation, engineering practice and other methods were used to study the distribution characteristics of lateral stress in the goaf, the variation law of outburst risk prediction indicators, and the reasonable location of the goaf roadway. The results indicate that there is a stress recovery effect in the fractured rock mass after the mining of the upper protective layer, and after the stress recovery, the peak lateral stress in the goaf will move towards the direction of the goaf; Based on the test results of coal outburst prediction indicators at different distances from the side of the goaf, sufficient pressure relief discharge area, effective pressure relief discharge area, and hazardous area were divided. Combined with engineering analogy, numerical simulation results, and the need to isolate gas in the goaf, a width of 5~7m was determined for the coal pillar along the goaf; After adjustment, the maximum values of outburst prediction indicators and return air gas concentration during tunnel excavation were 0.16mL/(g·min1/2) and 0.22%, respectively, with a decrease of 66% and 35.3% compared to before adjustment, ensuring the safety of roadway excavation and verifying the rationality of retaining coal pillars along the goaf.

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