采动动载作用下底板岩层裂隙演化规律的相似模拟研究  

Physical simulation testing research on mining dynamic loading effect and induced coal seam floor failure

作　　者：李海龙 白海波[2] 马丹[2,3] 田成东[2] 张奇 LI Hailong1＇2, BAI Haibo2, MA Dan2＇3, TIAN Chengdong2, ZHANG Qi2(1. School of Science, Shandong Jianzhu University, Jinan, Shandong 250101, China; 2. State Key Laboratory for Geomechanics and Deep Underground Engineering, China University of Mining ＆ Technology, Xuzhou, Jiangsu 221116, China 3. School of Resources and Safety Engineering Central South University, Changsha, Hunan 410083, Chin)

机构地区：[1]山东建筑大学理学院,山东济南250101 [2]中国矿业大学深部岩土力学与地下工程国家重点实验室,江苏徐州221116 [3]中南大学资源与安全工程学院,湖南长沙410083

出　　处：《采矿与安全工程学报》2018年第2期366-372,共7页Journal of Mining & Safety Engineering

基　　金：国家重点基础研究发展计划(973)项目(2013CB227900);高等学校学科创新引智计划项目(B07028)

摘　　要：在对多个矿区工作面进行现场探测发现工作面推过底板后的第一次顶板周期性垮落过程中,底板裂隙破坏深度会出现滞后加深的现象,为对这种特殊采矿地质现象进行分析,以某矿现场地质条件为依托,采用相似模拟手段,模拟采动动载作用下底板岩层裂隙演化规律。经研究发现:1)采空区底板岩层首次受顶板岩层垮落冲击作用后,底板岩层采动裂隙会出现滞后破坏加深的现象。在之后的2~3次顶板周期性垮落冲击过程中,底板岩层裂隙都有类似规律,但加深效果逐渐减弱;2)相似模拟试验的底板岩层位移与垂直应力监测结果证明了底板岩层经历了采前应力集中、采后膨胀泄压,采动动载冲击,采空区矸石充填平衡4个过程,底板裂隙的萌生、扩展以及再加深主要发生在1~2与2~3的转变过程之间,第4过程对底板裂隙的扩展实际是起到抑制作用的,底板破坏深度最大处一般出现在工作面推过测点后的1~2个周期来压至采空区底板被矸石充填压实之间这段距离,这也解释了为什么采空区滞后突水灾害时有发生;3)软弱底板岩层更易受采动影响,其位移与垂直应力的变化幅度较坚硬底板岩层而言明显偏大,但其底板裂隙发育深度和滞后破坏加深程度比坚硬底板岩层要弱。After detection of working face in many coal mines, we found that the phenomenon of delayed deepening on depth of floor crack failure occurs during the first roof periodic caving process when working face pasting the floor. In order to analyze the special geological phenomenon, we apply the similar simulation tests to investigate the evolution laws of floor rock fracture under the mining dynam- ic loading effects. Results show that： 1） The phenomenon of delayed deepening on depth of floor crack failure occurs when the floor rock in goal was mainly impacted by the roof rock caving. The similar rules on floor rock fracture occurs during the following 2-3 sub roof periodic caving, but the effect is gradually weakened. 2） Similar simulation test of floor strata displacement and vertical stress monitor- ing results show that the floor strata experiences four stages： including the mining stress relief, the min- ing depressurized, the mining burst load impact and the goaf backfilling balance. The floor crack initia- tion and expansion and deepening mainly happen in the change 1-2 and 2-3 stages, the fourth stage ac- tually plays inhibited effects on the floor crack expansion process. The maximum depth of destroyed floor generally happens in the distance of face passing the measuring point after 1-2 cycles in the working face pressure to goaf floor by backfilling compaction, which also explains why the lagging water inrush disasters occurs in mine gobs. 3） Weak floor strata are more easily influenced by mining and its changes of displacement and the vertical stress are obviously larger than that of the hard floor rock. However, the development depth and delayed deepening degree of floor crack failure are weaker than that of the hard floor.

关 键 词：底板破坏深度 相似模拟 采动动载 滞后破坏 

分 类 号：TU745[建筑科学—建筑技术科学]