高围压卸荷条件下横观各向同性岩体变形破坏与能量特征研究

发布时间：2018-05-30 02:47

本文选题：岩石力学 + 石英云母片岩　；参考：《岩石力学与工程学报》2017年08期

【摘要】：为揭示石英云母片岩变形及能量特征,针对平行片理和垂直片理方向的试件,基于MTS815岩石力学试验平台开展不同围压下的卸荷试验,分别从体积变形系数、能量比、能量变化率、能量应力增量比等方面系统研究高围压卸荷条件下石英云母片岩变形破坏特征及能量演化规律。结果表明:平行组试件径向变形发育能力及各特征应力量值均高于垂直组;其能量演化规律具有显著的围压效应,2组试件能量特性差异明显;与垂直组相比,平行组试件峰前、峰后应变能变化率较低且高围压下裂隙发育及塑性变形程度更高;提出能量应力增量比以表征试件能量变化对卸荷程度的敏感性,2组试件峰前能量应力增量比均随围压的增加而增加,但峰后弹性能应力增量比几乎不受初始围压的影响,垂直组峰前、峰后弹性能应力增量比和耗散能应力增量比量值均大于平行组。
[Abstract]:In order to reveal the deformation and energy characteristics of quartz mica schist rock, the unloading tests under different confining pressures were carried out on the basis of MTS815 rock mechanics test platform for specimens with parallel and vertical schist directions, respectively from volume deformation coefficient and energy ratio. The characteristics of deformation, failure and energy evolution of quartz mica schist under high confining pressure unloading are systematically studied in the aspects of energy change rate and energy stress increment ratio. The results show that the radial deformation development ability and characteristic stress values of parallel specimens are higher than those of vertical group, the energy evolution law of parallel group has obvious confining pressure effect and the difference of energy characteristic of two groups is obvious, compared with that of vertical group, the energy characteristic of parallel group specimen is before peak. The change rate of post-peak strain energy is lower and the degree of fracture development and plastic deformation is higher under high confining pressure. The sensitivity of energy change to unloading degree in two groups of specimens is presented. The ratio of energy stress increment before peak increases with the increase of confining pressure, but the increment ratio of elastic energy stress after peak is almost unaffected by initial confining pressure. The ratio of elastic energy stress increment and dissipative energy stress increment is larger than that of parallel group before and after the vertical peak.
【作者单位】：四川大学水力学与山区河流开发保护国家重点实验室;四川大学水利水电学院;
【基金】：国家重点基础研究发展计划(973)项目(2015CB057903) 国家自然科学基金资助项目(51079092)~~
【分类号】：TV223

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