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5~7 m;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0.16 mL/(g·min^(1/2))、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。
Based on the gas geological conditions of the extra-thick coal seam under the upper protective seam mining,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 after the upper protective layer mining,and after the stress recovery,the peak lateral stress in the goaf will move towards the goaf;Based on the test results of coal outburst prediction indicators at different distances from the side of the goaf,it was divided into sufficient pressure relief discharge area,effective pressure relief discharge area,and hazardous area.Combining with engineering analogy,numerical simulation results,and the need to isolate gas in the goaf,coal pillars were laid along the goaf with a width of 5~7 m;After adjustment,the maximum values of outburst prediction indicators and air return gas concentration during tunneling were respectively 0.16 mL/(g·min^(1/2))and 0.22%,with a decrease of 66%and 35.3%compared to that before adjusted,which ensured the safety of roadway development and verified the rationality of retaining coal pillars along the goaf.
作者
任启寒
REN Qihan(State Key Laboratory of Coal Mine Disaster Prevention and Control,Chongqing 400037,China;CCTEG Chongqing Research Institute,Chongqing 400037,China)
出处
《煤炭工程》
北大核心
2024年第6期21-27,共7页
Coal Engineering
基金
国家自然科学基金项目(52274246)
国家自然科学基金区域创新发展联合基金项目(U21A20110)
重庆市自然科学基金项目(CSTB2022NSCQ-MSX0276)。
关键词
保护层开采
特厚煤层
突出危险
侧向应力
煤柱宽度
protective seam mining
extra thick coal seam
outburst danger
lateral stress
coal pillar width
