循环载荷下岩体能量特征及变形参数分析  

ANALYSIS OF ENERGY CHARACTERISTICS AND DEFORMATION PARAMETERS OF ROCK MASS UNDER CYCLIC LOADING

作　　者：刘杰[1] 李建林[1] 张玉灯[2] 朱婷[1] 杨姗姗[1] 李映霞[1] 

机构地区：[1]三峡大学三峡库区地质灾害教育部重点实验室,湖北宜昌443002 [2]中国水电顾问集团贵阳勘测设计研究院,贵州贵阳550002

出　　处：《岩石力学与工程学报》2010年第A02期3505-3513,共9页Chinese Journal of Rock Mechanics and Engineering

基　　金：湖北省教育厅自然科学研究项目(Q20101201);三峡大学科学基金资助项目(KJ2009B061;KJ2009A033)

摘　　要：以RMT–150C岩石力学测试系统为平台,进行不同应力水平和加载速率条件下不同种类岩石材料的循环载荷试验。在对加、卸载应力–应变曲线进行分区的基础上,定义卸载过程中的能量消耗率,探讨岩石损伤破坏过程中能量的转化,同时定量分析弹性模量,泊松比和残余应变等变形参数的变化规律。研究结果表明:应力水平、加载频率越高,岩性越强,则滞回圈的面积,加载过程中做的功,卸载过程中释放的弹性能越大,岩石越软,能量消耗率越高;岩体未到达峰值抗压强度前,应力水平越高,弹性模量就越大,这说明在岩体抗压强度范围内,越高的载荷下,空隙和微缺陷被压密后,岩体相同载荷增量下的变形能力明显减弱。同时分析认为:频率升高到一定程度会导致疲劳强度的降低。整体而言,岩石轴向及横向相对残余应变均随着循环次数的增加而逐渐减小。Using RMT–150C rock mechanics test system,experimental tests of different kinds of rock materials under cyclic loading with the test condition of different stress levels and loading rates are carried out. Based on the division of stress and strain curves under loading and unloading conditions,the energy dissipation rate during unloading process is defined;and energy conversion during rock damage process is explored. Meanwhile,change laws of the deformation parameters such as the elastic modulus,Poisson′s ratio and residual strain are also analyzed quantitatively. The research results indicate that the higher the stress level and loading frequency are,the stronger the lithology is,the greater the hysteresis loop area,doing work the process of loading and the release elastic energy during the unloading process are;besides,the rock is softer,the energy conversion rate is higher. Before rock mass does not reach the peak value of compressive strength,the higher the stress level is,the greater the elastic modulus is,which shows that within the range of the rock mass compressive strength,with the higher loads,the deformation ability of rock mass under the same load increment weakens significantly when the gap and micro defect are compacted. Meanwhile,it can be given that fatigue strength will reduce when the frequency increases to a certain level. As a whole,the axial and lateral relative residual strains of rock decrease gradually with the increase in cycle numbers.

关 键 词：岩体力学 循环载荷 应力水平 加载速率 能量消耗率 变形参数 

分 类 号：TU45[建筑科学—岩土工程]