循环荷载下岩石疲劳寿命双因素模型实验研究ExperimentalStudyof.PDF

24 4 () Vol. 24 No. 4 2010 12 JournalofUniversity of South hina( Science and Technology) Dec. 2010 : 1673- 0062( 2010) 04- 0036- 06 循环荷载下岩石疲劳寿命 双因素模型实验研究 1 2 3 1 冯春林 ,冯超博 , 吴永丰, 冯福贤 ( 1. , 421001; 2. , 411100; 3. 219, 741025) : 通过对花岗岩白砂岩和大理岩的单轴压缩恒幅和变幅循环 载疲劳试验, 建立了一种测定岩石疲劳寿命双因素实验模型.试验表明, 变幅应力是影响疲劳寿命 的关键因素; 变幅应力的基础疲劳寿命比恒幅应力的降低 16. 9% ~ 18% , 临界应力 比降低 23. 0% ~ 28. 23%.尽管岩石的试验数据离散性很大, 但本实验模型对于测定 岩石全应力曲线非稳态区内的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; 因此该模型对岩石基础工程的设计和现场监测具有实用价值. : 岩石;循环 载; 疲劳寿命; 双因素模型;稳态;非稳态 : TU458 : A Experimental Study ofDual FactorM odel of Fatigue Life of Rock Subjected to CyclicLoading 1 2 3 1 FENG Chun lin, FENG Chao bo, WU Yong feng, FENG Fu xian ( 1. School ofNuclearResources andNuclear Fuel Engineering, University of South hina, H engyang, H unan 421001, hina; 2. Faculty of Energy Engineering, X iangtan University, X iangtan, H unan 411100, hina; 3. Gansu 219 Team Nuclear Industry, T ianshui, Gansu 741025, hina; ) Abstract: A dual factor expermi entalmodel of determ ining the fatigue life of rock was set up by the testing results of uniaxial compression, constant and variable cyclic loading of granite, white sandstone and marble. The testing results showed that variable amplitude stresswas the key factor affecting the fatigue life. Its basic fatigue lifewas 16. 9% to 18% lower than that of constant amplitude stress and its critical stress ratios decreased by 23. 0% to 28. 23%. In spite of aw ide discret