摘要
以典型断层型冲击地压矿井为例,采用相似材料模拟试验方法,基于覆岩空间结构失稳与断层活化耦合致灾原理,分析了巨型逆冲断层下盘煤层开采采场覆岩运动过程、工作面倾向支承压力及断层面的应力变化规律,研究了巨型逆冲断层影响下巨厚坚硬顶板易冲击煤层冲击地压显现特征。试验结果表明:煤层开采诱发巨型逆冲断层冲击灾变过程分为3阶段:第1阶段,受煤层采动影响,上覆岩层发生空间运动,煤体中形成明显高应力集中区;第2阶段,覆岩多层空间结构演化诱发断层活化,断层活化导致空间结构外部岩体回转,给空间结构施加外部载荷,造成空间结构失稳加剧,煤岩体的应力激增,影响范围扩大;第3阶段,断层滑移释放能量,提供动载荷。根据应力监测数据变化规律,划分了逆冲断层的明显影响区域,研究结果为断层影响下煤层开采的防冲策略与设计提供可靠依据。
Taking typical fault rockburst mine for example, using similar simulation test to analyze overlying strata movement and the stress variation rule of fault plane and dip abutment pressure after the coal seam of the giant thrust fault footwall has been exploited based on coupling disaster-causing mechanism between spatial structure instability of overlying strata and fault activation, and the rockburst characteristics of extra-thick hard roof and easy burst coal seam influenced by giant thrust fault are studied. The results show that there are three stages in rockburst catastrophe process of the giant thrust fault induced by mining ultra thick seam. The first stage, high stress concentration region forms under the influence of overlying strata movement when mining coal seam. The second stage, overlying strata spatial structures evolution induce fault activation, and fault activation leads to external rock mass of spatial structures rotation applying extraneous load to spatial structures, causing instability increased, stress increased and influence scope enlarged. The third stage is the fault slip with releasing energy and providing dynamic load . Ultimately, the scope of significantly affect areas of thrust fault is delimited combining with the stress observation data. The results provides reliable basis for the protection strategy and control design of rockburst for coal mining influenced by giant thrust fault.
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2014年第9期2486-2492,共7页
Rock and Soil Mechanics
基金
国家重点基础研究发展计划(973计划)项目(No.2010CB226803)
国家自然科学基金面上项目(No.11072102)
关键词
巨型逆冲断层
深部煤层
断层活化
冲击灾变
相似试验
giant thrust fault
deep coal seam
fault activation
rockburst catastrophe
similar experiment
