三轴压缩下石英云母片岩能量特征及其本构模型研究  

Study on energy characteristics of mica-quartz schist under triaxial compression and its constitutive model

作　　者：谢科 卓莉[1,2] 肖明砾[1,2] 谢红强[1,2] 何江达[1,2] XIE Ke;ZHUO Li;XIAO Mingli;XIE Hongqiang;HE Jiangda(State Key Laboratory of Hydraulics?ind Mountain River Engineering,Sichuan University,Chengdu 610065,Sichuan,China;College of Water Resources and Hydropower,Sichuan University,Chengdu 610065,Sichuan,China)

机构地区：[1]四川大学水力学与山区河流开发保护国家重点实验室，四川 成都 610065 [2]四川大学水利水电学院，四川 成都 610065

出　　处：《水利水电技术》2018年第3期157-163,共7页Water Resources and Hydropower Engineering

基　　金：国家重点基础研究发展计划(973计划)(2015CB057903);国家自然科学基金资助项目(51079092)

摘　　要：为了研究某水电站引水隧洞石英云母片岩物理特性,利用MTS815岩石力学试验平台,分析其三轴压缩试验数据,揭示了石英云母片岩常规三轴压缩条件下能量特征并引入了能量损伤D,基于Hooker定理建立了石英云母片岩的能量损伤本构模型。研究结果表明:相同围压下,平行组试件的可释放弹性应变能增长速率大于垂直组,平行组试件峰值应变能大于垂直组;垂直组试件的耗散能增长速率大于平行组。相同围压和轴向应变下,垂直组的耗散能大于平行组。随着围压的增大,平行组和垂直组峰值点和残余点可释放应变能均增大,两者表现出较好的线性关系且相关系数均大于98%。定义弹性应变能存储比,数值在未超过阀值应力σs时,保持在1左右,而在超过阀值应力σs后,与轴向应变呈现良好的指数关系且相关系数均达到97%。该模型能很好的描述石英云母片岩三轴压缩的应变软化和硬化过程。研究成果能够为工程设计提供合理的力学参数,并且对于各向异性岩石的物理特性研究具有参考价值。In order to study the physical characteristics of the mica-quartz schist at the diversion tunnel of a hydropower station,the energy characteristics of the mica-quartz schist under the conventional triaxial compression condition is revealed through the analysis made on its triaxial compression testing data with the MTS815 rock mecheinics testing platform,while the energy damage constitutive model is established by introducing the energy damage D based on Hooker theorem.The study result shows that under the same confining pressure,the increasing rates of the releasable elastic strain energies of the specimens from the parallel group are larger than those from the vertical group and the peak strain energies of the specimens from the parallel group are larger than those form the vertical group,while the increasing rates of the dissipated energies of the specimens from the vertical group are lar-ger than those from the parallel group.Under the same confining pressure and axial strain,the dissipated energies from the verti-cal group are larger than those from the parallel group.Following with the increase of the confining pressure,the releasable strain energies at the peak points and the residual points of both the parallel group and the vertical group are to be increased.Both of them exhibit better linear relationships with the correlation coefficients of over 98%.The value of the defined elastic strain energy storage ratio remains at about 1,when it is not over the threshold stress as,while it presents a better exponential relationship to the axial strain with the correlation coefficient of 97%,when it is over the threshold stress crs.This model can better describe the strain-softening and the strain-hardening processes of the mica-quartz schist under the triaxial compression.The study result can not only provide reasonable mechanical parameters for the design of the project,but also has a referential value for the study made on the physical characteristics of the anisotropic rock.

关 键 词：石英云母片岩 各向异性 三轴压缩试验 能量特征 本构模型 

分 类 号：TU44[建筑科学—岩土工程]