围压条件下岩石循环冲击损伤的能量特性研究  

RESEARCH ON ENERGY PROPERTIES OF ROCK CYCLICAL IMPACT DAMAGE UNDER CONFINING PRESSURE

作　　者：许金余[1,2] 吕晓聪[1,3] 张军[3] 王泽东[1] 白二雷[1] 

机构地区：[1]空军工程大学工程学院,陕西西安710038 [2]西北工业大学力学与土木建筑工程学院,陕西西安710072 [3]北京军区空军后勤部机营处,北京100005

出　　处：《岩石力学与工程学报》2010年第A02期4159-4165,共7页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(51078350)

摘　　要：在不同围压等级和冲击荷载循环作用下,利用带围压装置的霍普金森压杆设备,对斜长角闪岩、绢云母石英片岩和砂岩的动态力学性能进行试验研究,得到不同循环作用次数下岩样的应力–应变曲线。通过理论分析建立岩石损伤度的判定标准,并定义累积比能量吸收参量来表征围压条件下岩样冲击损伤的能量特性。3种岩石损伤度与围压和累积比能量吸收值的关系研究表明:累积比能量吸收参量能很好的描述围压条件下岩样的冲击损伤程度,岩石循环冲击损伤演化过程存在围压效应,当围压逐渐增大时,岩石损伤度的增加随累积比能量吸收值增加的趋势变缓,其抗冲击损伤的能力增强,即围压越高,试件达到相同损伤度所需要耗散的能量越多。得出围压条件下岩石损伤度与累积比能量吸收值的关系式。随着围压的增加,砂岩达到损伤阈值时的累积比能量吸收值增长率最大,斜长角闪岩次之,绢云母石英片岩最小。Dynamic mechanical performance experiments were carried out for three types of rocks under different confining pressures and cyclical impact loadings by using split Hopkinson pressure bar with confining pressure device. The stress-strain curves of specimens under cyclical impact loadings were obtained. According to theoretical analysis,a determinant criterion of damage degree of rock was established;and the accumulative specific energy absorbency was defined to describe energy properties of rock dynamic damage. The studies of the relationships among damage degree of rock,accumulative specific energy absorbency and confining pressure under cyclical impact loadings show that accumulative specific energy absorbency could well describe the damage degree of rock. When the confining pressure increases gradually,the incremental tendency of damage becomes slow along with the accumulative specific energy absorbency,i.e.,the higher the confining pressure is,the more energy for rock to reach the same damage level is needed. The formulae of rock damage degree and accumulative specific energy absorbency are put forward under confining pressures. When the damage threshold is reached,the growth rate of accumulative specific energy absorbency of sandstone is the largest along with the increase in confining pressure,the rate of sericite quartz schist is the smallest,and the rate of plagioclase amphibolite is between ones of sandstone and sericite quartz schist.

关 键 词：岩石力学 损伤度 累积比能量吸收 围压 

分 类 号：TU452[建筑科学—岩土工程]