中文摘要：

为深入研究循环加卸载作用下岩体的变形规律，针对三峡库区砂岩进行了56组循环加卸载试验。根据试验的不同步现象，对应力-应变滞后概念进行修正：（1）应力超前于应变和应力滞后于应变现象共存，故将“应力-应变滞后现象”更名为“应力-应变不同步现象”更为合理；（2）在应力-应变不同步现象的基础上，应考虑应力速率-应变速率的不同步现象。通过分析循环加卸载试验的不同步机制，提出应力-应变吸引点、应力速率-应变速率吸引点、应力-应变补偿机制和应力速率-应变速率补偿机制4个概念，并且得到：应力-应变同步与应力速率-应变速率同步不能同时出现：不同步现象是必然而同步仅存在于某一时刻点；应力-应变处于螺旋式循环递进的过程。基于循环加卸载试验，首次发现应力速率-应变速率不同步现象，在不同步现象中提出了3个不同步阶段的定义，并通过分析预测变形速率-实际变形速率、表观弹性模量以及岩样的瞬时泊松比随时间的变化规律，提出3种对不同步阶段定量判别的方法。此外，基于同频率不同峰值强度下试验得到，随着峰值强度f（t）的增加，岩样的E（t）值逐渐增加，式E（t）=af（f）＋b吻合度也逐渐增加。

英文摘要：

In order to study the deformation of rock under cyclic loading and unloading, the tests to the 56 sandstone samples from Three Gorges Reservoir area were carried out. The concept of stress-strain hysteresis was modified according to the asynchronous phenomenon from the tests. The phenomena that the stress is ahead of or behind the strain exist at the same time, so it is more reasonable that the hysteresis phenomenon of stress-strain is named as the stress-strain asynchronous phenomenon. On the basis of the stress-strain asynchronous phenomenon, the asynchronous phenomenon of the stress rate-strain rate should be considered. After the analysis of the asynchronous mechanism of the cyclic loading and unloading test, four.concepts, the stress-strain attraction point, the stress rate-strain rate attraction point, the stress-strain compensation mechanism and the stress rate-strain rate compensation mechanism, were proposed. Three findings were obtained. The stress-strain and stress-strain ratesynchronization ~did not occur simultaneously. The asynchronous phenomenon is inevitable and synchronous phenomenon only exists at a certain point. The relationship of stress-strain is the process of spiral cycle progression. The asynchronous phenomenon of the stress rate-strain rate was found for the first time in the cyclic loading and unloading tests and the definition of three asynchronous stages was proposed. The predicted and actual deformation rate, the apparent elastic modulus and the instantaneous Poisson ratio of the samples with the time were analyzed and three methods were put forward to judge the asynchronous stages quantitatively. Besides, by analyzing the mechanism of stress-strain rate based on the same frequency and different peak strength tests, a conclusion is reached that the E（t） of the sample and the coincidence degree of E（t） = af（t） ＋ b increases with the increase of the peak intensity.