摘要
在单轴压缩、恒幅和变幅下,分别对花岗岩、白砂岩和大理岩进行循环荷载疲劳试验,建立了一种测定岩石疲劳应变率双因素实验模型.实验结果表明,变幅应力是影响岩石疲劳变形特性的主要因素;变幅与恒幅应力相比,变幅应力的基础疲劳寿命和临界强度分别降低了15.8%~18.0%和21.6%~25.8%,临界应变率增加了17.3%~21.3%.尽管岩石的试验数据离散性很大,但该模型对于测定岩石的疲劳应变率和疲劳寿命具有良好的适应性;与传统方法相比,它更准确、更符合实际;该模型对岩石疲劳变形规律的研究和岩石基础工程长期稳定性监测具有实用价值.
A dual factor experimental model of determining the strain rate of rock was set up by the testing results of uniaxial compression,constant and variable amplitude cyclic loading of granite,white sandstone and marble.The testing results show that the variable amplitude stress was the main factor of affecting the fatigue deformational property.In contrast to the constant amplitude stress,its basic fatigue life and the critical strength was,decreased by 15.8%~18.0%,21.6%~25.8%,and the critical strain rate was increased by 17.3% to 21.3%.In spite of a wide discreteness of test data of rock,the experimental model has a good adaptability with the determining rock＇s the fatigue strain rate in the unsteady zone of complete stress-strain curve.The test model was even more exact,than the tradition model.It would have the practical value for the study of fatigue deformational rule and the assessment of long-term stability in the rock base engineering.
出处
《交通科学与工程》
2011年第1期55-63,共9页
Journal of Transport Science and Engineering
基金
国家自然科学基金项目(50904036)
关键词
岩石
应变率
双因素模型
恒幅和变幅应力
循环荷载
rock
strain rate
dual factor model
constant and variable stress
cyclic loading
