摘要
冲击地压是目前我国煤矿开采发生的主要动力灾害之一,并常发生在断层、褶曲和煤层变化带等构造异常区域,给矿井造成严重的破坏后果。针对断层冲击地压频繁发生的情况,采用相似模拟和数值模拟的方法,对断层冲击地压发生过程及其应力场演化规律进行了研究;并基于"粘滑理论",从力学的角度对断层冲击地压发生机制进行了阐释。研究结果表明:工作面接近断层时,断层冲击地压的发生过程可分为"起始活化"—"剧烈活化—"冲击显现"三个阶段;开采活动引起了覆岩破坏,导致裂隙带向断层扩展,断层应力场受到扰动,从而诱发了断层冲击地压;采动影响使得断层带应力场呈现应力比先减小后增大的变化规律,当应力比达到极值时,断层错动失稳;开采扰动导致断层开始粘滑的临界剪应力值降低,使得断层剪应力更易达到该阈值,是断层冲击地压的根本原因。
Rock-burst is one of the major dynamic disasters in coal mines,which usually occurs at some complex tectonic areas such as fault,fold and changing zone of coal seam,causing serious damage to mine. Based on the fact that fault rock-burst occurs frequently,similar simulation and numerical simulation were used to study the process of fault rock-burst and the law of stress evolvement in fault system. Furthermore,mechanical analysis of fault rock-burst is interpreted based on stick-slip theory. Four conclusions are drawn. Firstly,development of fault rock-burst can be divided into three stages,namely 'early activation','intense activation'and 'instability '. Secondly,it is the expanding of strata damage to the fault causing by mining activities that induce changes of faults ' stress field.Thirdly,stress ratio of shear stress and normal stress decreases first and increases lately in the fault zone by mining,and the fault will slide when the ratio reaches a critical value. Lastly,the maximum friction along the fault decreases as mining and that makes the shear stress easily to reach the maximum friction,then fault rock-burst occurs.
出处
《地下空间与工程学报》
CSCD
北大核心
2016年第S2期894-898,共5页
Chinese Journal of Underground Space and Engineering
基金
国家自然科学基金(51304117
5157041403)
中煤科工集团科技创新基金重点项目(2014ZD008)
关键词
断层冲击地压
粘滑
临界剪应力
覆岩破坏
应力比
fault rock-burst
stick-slip
critical shear stress
overburden failure
stress ratio
