摘要
深部开采引起的煤岩卸荷损伤破坏的机理与连续加载机理不同,从卸荷的角度研究煤岩动力灾害成为研究煤岩动力灾害问题的一个新的发展方向。利用MTS815岩石力学测试电液伺服试验系统和8CHS PCI-2声发射检测系统,对煤岩卸荷变形损伤及声发射特性进行了研究。研究表明,煤岩卸荷破坏表现为强烈的脆性破坏,且具有突发性,多呈张剪复合型破坏形式;煤岩卸荷的累积声发射振铃计数演化曲线可反映煤岩卸荷损伤的演化过程;煤岩卸荷破坏过程可分为3个阶段:损伤弱化阶段、损伤稳定发展阶段、损伤加速发展阶段;在煤岩开采过程中,围压被卸除,煤岩体迅速进入到煤岩卸荷损伤破坏的第3阶段,损伤迅速累积并发生突发性断裂破坏,煤岩动力灾害随即发生。
The damage failure mechanisms of coalrock under unloading condition during deep mining is different from those under traditional loading condition, starting from the unloading condition position to study the dynamic disaster of coalrock has become a new direction in the disaster study. The rock mechanics electrohydraulic servo test system （MTS815） and acoustic emission system （8CHS PCI-2） are used to study the coalrock deformation damage and acoustic emission （AE） characteristics. The results show that the failure of coalrock under unloading condition exhibits strong brittleness and happens in sudden and is mostly of tensile shear failure type. The evolution curve of cumulative ring-down count of acoustic emission can better reflect the coalrock unloading damage evolution process, and the whole unloading failure process can be divided into three stages： the stage of damage weakening, damage stably development stage and the stage of accelerated damage development. During the mining process the confining pressure of the coalrock is unloaded, the coalrock rapidly arrives at the third stage of the whole unloading failure process, and the damage is accumulated rapidly and the fracture failure of coalrok occurred suddenly, then follows the coalrock dynamic disaster.
出处
《土木建筑与环境工程》
CSCD
北大核心
2009年第2期57-61,共5页
Journal of Civil,Architectural & Environment Engineering
基金
国家自然科学基金资助项目(50504011)
关键词
煤岩动力灾害
卸荷
声发射
损伤
coalrock dynamic disaster
unloading condition
acoustic emission
damage
