膨胀土损伤变量不同表征方法评价的试验研究

发布时间：2018-05-29 07:54

本文选题：损伤变量 + 表征　；参考：《岩土力学》2015年10期

【摘要】：裂隙性是膨胀土的重要结构特征,裂隙损伤对膨胀土的变形、强度和稳定性有重要影响。岩土体损伤演化理论是当前研究的前沿课题,选择合理的损伤变量决定着损伤模型的正确性。为评价几种损伤变量表征方法的合理性,以南水北调中线工程陶岔引水渠坡的膨胀土为试验研究对象,通过控制净围压和吸力分别为100、50 k Pa下的CT-三轴剪切试验,定量研究了分别基于承载面积、CT数的均值ME和方差SD的损伤变量表征方法的合理性。研究发现,损伤面积相同而损伤部位不同的试样偏应力-应变曲线和强度基本一致;损伤面积和SD可以作为损伤变量表征参数,而ME不适合用来表征膨胀土的损伤变量,虽然ME可以很好地用来定义岩石的损伤变量。试验研究结果可以为建立考虑损伤的膨胀土强度理论和本构模型中损伤变量的选择、定义提供科学依据。
[Abstract]:Fracture is an important structural feature of expansive soil, and crack damage has an important effect on deformation, strength and stability of expansive soil. The damage evolution theory of rock and soil is a frontier subject of current research. The correctness of damage model is determined by selecting reasonable damage variables. In order to evaluate the rationality of several damage variable characterization methods, the expansive soil on the slope of the diversion channel in the middle route project of South-to-North Water transfer Project was used as the experimental object. The CT-triaxial shear test was carried out under the control of net confining pressure and suction of 100 ~ 50 KPA, respectively. The rationality of the damage variable representation method based on the mean ME and variance SD of CT number of bearing area is studied quantitatively. It is found that the strain curve and strength of specimens with the same damage area and different damage sites are basically the same, the damage area and SD can be used as parameters of damage variable, but ME is not suitable to characterize the damage variable of expansive soil. Although ME can be used to define rock damage variables. The experimental results can provide a scientific basis for establishing the strength theory of expansive soil with damage and the selection of damage variables in constitutive model.
【作者单位】：西南大学工程技术学院;后勤工程学院建筑工程系;
【基金】：国家自然科学基金(No.11572262,No.51208078) 中央高校基本科研业务费专项资金资助(No.XDJK2015C018)
【分类号】：TU443

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