摘要
为研究深部高应力岩体开挖卸荷对围岩的影响,运用自制的带轴向静压和围压装置的霍普金森压杆(SHPB)设备,开展不同速度围压卸荷试验。结合围压卸荷过程砂岩试样声发射特性及动态加载后试样破碎块度分维特性,分析围压卸荷速率对试样损伤的影响。试验结果表明:当卸荷速率在0.5～10 MPa/s范围内变化时,砂岩损伤、声发射能量及破碎分形维数随围压卸荷速率增大而增大;但当卸荷速率增大到200 MPa/s时,砂岩损伤、声发射能量及破碎分形维数反而减小。在一定范围内提高围压卸荷速率,有助于提高砂岩试样裂隙发育及损伤程度。
In order to research influence of excavation unloading on surrounding rock of high stress rock mass, unloading confining pressure tests of sandstone were conducted with a modified triaxial split Hopkin- son pressure bar （SHPB） coupled static and dynamic loads. Based on the unloading confining pressure tests with triaxial high stress under conditions of different unloading rates, the effects of unloading rate of confining pressure on rock damage were analyzed by acoustic emission and fractal dimension characteristics with the confining pressure unloading process. The results show that varies in the range of 0.5- 10 MPa/s, the damage variable and acoustic emission energy and fractal dimension of sandstone gradually increase with the unloading rate, that when the unloading rate reaches 200 MPa/s, the damage variable and acoustic emission energy and fractal dimension decrease, and that within a certain range, the increase in the unloading rate contributes to the sandstone test sample＇s greater crack and damage growth degrees.
出处
《中国安全科学学报》
CAS
CSCD
北大核心
2013年第1期90-94,共5页
China Safety Science Journal
基金
国家自然科学基金重点项目(50934006),国家自然科学基金资助(51174003)
国家重点基础研究发展计划“973”项目(2010CB226806)
安徽理工大学青年教师科学研究基金资助(2012QNY39)
关键词
围压卸荷
损伤
动静组合加载
动态破碎
声发射
unloading confining pressure
damage
coupled static and dynamic loads
dynamic fragmentation
acoustic emission
作者简介
殷志强（1983-），男，安徽萧县人，博士，讲师，主要从事岩石动态力学特性、矿山动力灾害方向的教学与研究工作。E—mail：zhqyin@aust．edu．cn．
教授
