深部采煤诱发矿震的覆岩关键层破断特征研究
On the fracture characteristics of overlying key strata related to the seismicity under deep coal mining
邹俊鹏 1周祝 1焦玉勇 1张全 1张泉 2李振国2
作者信息
- 1. 中国地质大学(武汉)工程学院,湖北武汉 430074
- 2. 兖矿能源集团股份有限公司,山东济宁 273500
- 折叠
摘要
深部煤炭资源开采过程中,强矿震事件屡有发生,已经成为制约深部煤矿安全高效生产的重要原因.以东滩煤矿63上06工作面为研究背景,运用PFC2D数值软件模拟煤层开采过程中上覆多关键层的破坏过程,分析其采动应力场变化规律,并运用单广义位移厚梁力学理论推导多关键层破断的力学机制.结果表明:上覆关键层的破断模式分为悬空破断和悬伸破断2种;因采动应力场变化的力拱效应,煤层采动过程中上覆关键层竖直应力逐渐减小,而水平应力增加;推导了关键层悬空破断和悬伸破断前受到的最大拉应力公式和最大悬空距和悬伸距,揭示了深部采煤上覆关键层破断力学机制.研究结果对于发展和完善深部采煤覆岩运移理论具有重要的意义.
Abstract
In the process of mining deep coal resources,the occurrence of strong mine earthquakes has become an important reason restricting the safe and efficient production of deep coal mines.The sudden release of strain energy caused by the instant breaking of key strata in deep coal mining is one of the important causes of the mining-induced seismicity.Aiming at the 63upper06 working face of the Dongtan coal mine,the PFC2D numerical software is used to simulate the failure process of overlying key strata in the process of coal mining.The evolution of the mining stress field is also investigated.Utilizing the single generalized displacement thick beam mechanics theory,the mechanical process of multiple key strata is inferred.The results indicate that the overlaying key strata failure types could be classified as suspended failure and overhanging failure.The vertical stress in overlying strata steadily decreases while the horizontal stress rises during mining as a result of the force arching effect of the changing mining stress field.The maximum tensile stress formula,maximum suspension distance,suspension distance of key strata before suspension,and mechanical mechanism of key strata covering deep coal mining are all derived.The research results are of great significance for the advancement of the theory of coal overburden migration in deep mining.
关键词
岩石力学/深部煤矿/关键层破断/PFC2D/采动应力场变化/力学机制Key words
rock mechanics/deep coal mine/breaking of key layers/PFC2D/change of mining stress field/mechanical mechanism引用本文复制引用
基金项目
国家自然科学基金资助项目(42177152)
国家自然科学基金资助项目(41902293)
国家公派留学基金项目(202206410027)
出版年
2024
NETL
NSTL
万方数据