三向应力状态下冻融岩石损伤本构模型

发布时间：2018-07-06 17:29

本文选题：围压 + 冻融循环　；参考：《岩土工程学报》2017年08期

【摘要】：充分考虑岩石材料缺陷随机性的特点,基于连续损伤力学理论,建立了考虑围压影响的冻融荷载作用损伤模型;根据红砂岩变形破坏曲线的几何条件,采用全微分方法确定了仅含岩石基本特征参量的模型参数表达式;通过红砂岩冻融循环力学特性试验,验证了模型的合理性。研究表明:红砂岩以裂纹为主导的细观力学响应与宏观变形破坏特性相一致;随着冻融循环次数的增加,岩石损伤程度加剧,宏观上表现为材料力学性能的劣化。但在变形中后期,相同损伤程度时岩石应变增加,塑性特性增强;围压可改善岩石受力状态,因而随着围压的增加,岩石损伤程度减小,宏观上表现出材料抵抗破坏能力的增强和塑性变形的增加。
[Abstract]:Considering the characteristics of the randomness of rock material defects, based on the theory of continuous damage mechanics, the damage model of freezing and thawing loading considering the influence of confining pressure is established. According to the geometric condition of the deformation and failure curve of the red sandstone, the model parameter expression of the basic characteristic parameter of the rock is determined by the full differential method, and the freeze-thaw through the red sandstone is followed. The study shows that the micromechanical response dominated by the crack is consistent with the macroscopic deformation failure characteristics. With the increase of the number of freeze-thaw cycles, the damage degree of the rock is aggravated and the mechanical properties of the material are deteriorated at the macroscopic level. But in the middle and late stages of the deformation, the same damage degree rock. The rock strain increases and the plastic property is enhanced, and the confining pressure can improve the stress state of the rock. As the confining pressure increases, the damage degree of the rock decreases, and the strength of the material resistance to failure and the increase of the plastic deformation are shown on the macro.
【作者单位】：西安科技大学力学系;广西建工集团基础建设有限公司;西安科技大学建筑与土木工程学院;
【基金】：国家自然科学基金项目(11172232,41272340,41302228,41672305) 中国博士后科学基金项目(2014T70931) 陕西省重点科技创新团队计划项目(2014KCT-30)
【分类号】：TU45

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