循环加卸载过程中砂岩能量耗散演化规律  

The evolution of sandstone energy dissipation under cyclic loading and unloading

作　　者：邓华锋[1,2] 胡玉[1,2] 李建林[1,2] 王哲[1,2] 张小景[1,2] 胡安龙[1,2] 

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]三峡大学三峡地区地质灾害与生态环境湖北省协同创新中心,湖北宜昌443002

出　　处：《岩石力学与工程学报》2016年第A01期2869-2875,共7页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(51309141);湖北省自然科学基金重点项目(2015CFA140);三峡大学研究生科研创新基金项目(2015CX017)~~

摘　　要：为了深入分析循环加卸载过程中岩石能量耗散演化规律,设计、进行砂岩的单轴循环加卸载试验。详细分析典型循环加卸载滞回圈曲线变化特征,探讨加卸载过程中的总功、弹性变形能、耗散能、能量耗散率、残余应变、损伤变量等参数的变化规律及其相互关系。结果表明:(1)循环加卸载过程中,应力–应变滞后现象明显,而且存在明显的残余应变,在计算各能量参数时应该考虑这些因素的影响;(2)考虑残余变形和滞后效应的影响,提出循环加卸载过程中各能量参数修正的计算方法;(3)岩样在循环加卸载临近破坏的时候,各能量参数及残余应变出现明显的增大,能量参数和残余应变的突变均可以较好地预测岩样的破坏;(4)能量耗散率与残余应变的相关性也从另一个角度说明了在能量参数计算时不可忽略残余应变的影响。研究成果对岩石循环加卸载过程中岩石能量损伤演化规律分析具有较好的参考价值。To analyze the evolution law of rock energy dissipation, a series of uniaxial cyclic loading and unloading tests for sandstone have been designed and conducted. The typical cyclic loading and unloading hysteresis loop characteristic curve has been analyzed in detail, the variation and relationship of the total power, the elastic deformation energy, dissipated energy, energy dissipation rate, residual strain, damage variable and some other parameters during loading and unloading process have been discussed. The results showed that- （1） during cyclic loading and unloading process, the stress-strain hysteresis is obvious, and there is significant residual strain, whose effects should be considered in the calculation of the energy parameters. （2） Considering the impact of residual deformation and hysteresis effects, modified calculation methods of energy parameters during cyclic loading and unloading process have been proposed. （3） When rock samples is close to failure during the cyclic loading and unloading process, there is a significant increase for the energy parameters and residual strain, and the energy parameters and residual strain can effectively predict the destruction of rock samples. （4） The correlation of energy dissipation rate and residual strain shows from another perspective that the residual strain cannot be ignored in the calculation of energy parameters. The research results have a good reference value for the analysis of rock damage evolution law during cyclic loading and unloading process.

关 键 词：岩石力学 循环加卸载 耗散能 残余应变 滞后效应 损伤演化 

分 类 号：TU45[建筑科学—岩土工程]