摘要
为研究岩石在循环冲击荷载作用下的损伤规律,设计了3组试验,考虑了围压、荷载冲量大小和冲击次数对岩石损伤程度的影响。通过对大理石试件在压力试验机上的模拟冲击加载,测试受冲击后试件轴向超声波波速,并用超声波波速变化量描述试件的损伤度,得出了大理石试件的冲击损伤度与围压大小、荷载冲量大小和冲击次数的相关性。结果表明:在围压相同的情况下,岩石的循环冲击损伤与冲击次数和荷载冲量有关;在荷载冲量相同时,岩石的循环冲击损伤与冲击次数和围压有关;围压的存在提高了岩石的冲击强度,降低了岩石的损伤演化速率;围压效应的显现与冲击荷载的等级有关。
Three groups of experiments are designed to study the damage evolution law of rock under cyclical impact loadings. In these experiments, different grades of confining pressures, impulsive forces and times of shock are considered to have some effects on the damage degree evolution of rock. Simulating impact loadings to marble test cylinders have been accomplished on compression test machine; and the velocities of ultrasonic in damaged marble test cylinders are actually measured. The variation of ultrasonic velocity is used to describe the damage degree evolution of rock under the actions of cyclical impact loadings. The influence regulation of impulsive force and times of shock on the damage degree evolution under cyclical impact loadings are obtained. The results illustrate that the damage degree evolution of marble test cylinders have close correlations with confining pressures, the grades of impulsive force and the times of shock. Under the same confining pressure grade, the damage evolution is determined by the times of shock and the grade of impulsive forces. When the grade of impulsive forces keeping unchanged, the damage evolution is determined by the times of shock and the grade of confining pressures. As confining pressure being raised, the damage depth evolution speed of marble test cylinder under the same cyclical impact loading is reduced with the increasing of times of shock. It is also proved that the effect of confining pressure on the damage degree evolution is affected by the grades of impulsive force under the same shock times. The existence of confining pressure increases the impulsive strength of marble test cylinders.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2005年第22期4094-4098,共5页
Chinese Journal of Rock Mechanics and Engineering
关键词
岩石力学
循环冲击荷载
损伤规律
围压效应
rock mechanics
cyclical impact loadings
damage evolution law
confining pressure effects
