高强度开采工作面煤岩灾变的推进速度效应分析  

Advancing rate effect on rock and coal failure format in highintensity mining face

作　　者：杨胜利[1,2,3] 王兆会[1,2] 蒋威[1,2] 杨敬虎 

机构地区：[1]中国矿业大学(北京)资源与安全工程学院,北京100083 [2]放顶煤开采煤炭行业工程研究中心,北京100083 [3]煤矿安全高效开采省部共建教育部重点实验室,安徽淮南232001

出　　处：《煤炭学报》2016年第3期586-594,共9页Journal of China Coal Society

基　　金：国家重点基础研究发展计划(973)资助项目(2013CB227903);国家自然科学基金资助项目(51574244);煤矿安全高效开采省部共建教育部重点实验室开放基金资助项目(JYBSYS2014107)

摘　　要：高强度开采工作面煤岩灾变存在冲击特征,采场围岩控制困难。采用室内试验、理论分析及数值模拟等综合研究方法,分析高强度开采条件下煤岩变形破坏和围岩应变能分布特征,并揭示采场煤岩动力灾变发生机制。研究表明:煤岩属于率相关材料,随着加载速率的提高,受压煤岩破坏形式由静态变为动力破坏,在后破坏阶段,存储于煤岩中的应变能降低形式以塑性功耗散转变为整体破坏后的快速释放,破坏用时减小;随着工作面推进速度提高,煤壁前方煤体中最大主应力加载速率和最小主应力卸载速率均增大,浅部煤体应变能密度升高,致使围岩发生动力灾变概率和危害程度升高;基本顶突然断裂和滑落,将贮存于顶板中的应变能快速释放并向下位煤岩传递,使煤层中应变能密度迅速升高,促使煤岩发生动压冲击性煤壁破坏;基本顶断裂前、后,煤体中应变能密度峰值点之间距离为超前段回采巷道动力灾变危险区,是采场围岩控制的重点区域。Dynamic failure or even rock burst makes it difficult to keep surrounding rock stay in good control in highintensity mining face. Experimental,theoretical and numerical simulation methods are used in this study to analyzegeotechnical material failure feature and strain energy distribution formation in the surrounding rock under intense min-ing activity and,moreover,mechanism of dynamic failure of the surrounding rock is studied. Rock and coal specimensshow static failure formation under low loading rate,but it transits into dynamic failure gradually with increase of theloading rate. Geotechnical material belongs to loading rate dependent material which means the stress state may not besubject to the consistent condition. So the rock and coal may present dynamic failure if the loading rate is too high.With increase of the face advancing rate,loading rate of the major principal stress and unloading rate of the minor prin-cipal distributed in the coal seam are rising which may lead to dynamic catastrophe of the surrounding rock. Strain en-ergy density of the coal near the void space is high and the energy dissipated by the main roof at the fracturing timelead to sudden growth of the strain energy density in the coal which make coal spalling show dynamic features. The dis-tance between positions of the peak point of the strain energy in the coal seam before and after the fracture of the mainroof is the key area of the surrounding rock control.

关 键 词：高强度采场 煤岩 灾变 应变能密度 推进速度 

分 类 号：TD323[矿业工程—矿井建设]