干湿循环作用下砂岩细观损伤演化及宏观劣化研究
发布时间：2018-11-24 10:37
【摘要】：针对周期性干湿循环作用下岩石损伤劣化问题,以三峡库区某边坡的中风化砂岩为研究对象,分别对不同干湿循环次数作用下"干燥"和"饱和"状态的砂岩进行全断面CT扫描试验、巴西劈裂试验、单轴和三轴压缩试验。试验结果表明:在相同的干湿循环次数n下,"干燥"状态下砂岩的宏细观力学参数大于"饱和"状态下的参数;各典型区域的CT数均值随着循环次数非线性累积增加,初期变化较快,当n≥3时,细观损伤演化速度趋于缓慢;砂岩单轴抗压强度、弹性模量、抗拉强度、黏聚力、内摩擦角随n的增加呈对数下降,泊松比随n的增加而增大。干湿循环作用对砂岩不同力学参数的劣化程度不一,岩样"抵抗拉伸性能"大于"抵抗压缩性能"对水的敏感性。基于试验数据拟合,对不同干湿循环作用下两种含水状态的砂岩M C屈服准则进行了修正,为工程中获得任意围压下岩石的破坏强度提供了理论依据。
[Abstract]:Aiming at the problem of rock damage and deterioration under periodic dry-wet cycle, the middle weathered sandstone of a slope in the three Gorges reservoir area is taken as the research object. The full section CT scan test, Brazilian splitting test, uniaxial and triaxial compression test were carried out on the sandstone under different dry and wet cycles. The experimental results show that under the same dry-wet cycle times n, the macro and meso-mechanical parameters of sandstone in "dry" state are larger than those in "saturated" state. The mean value of CT number in each typical region increases with the nonlinear accumulation of cycle number and changes rapidly at the initial stage. When n 鈮，
本文编号：2353370
[Abstract]:Aiming at the problem of rock damage and deterioration under periodic dry-wet cycle, the middle weathered sandstone of a slope in the three Gorges reservoir area is taken as the research object. The full section CT scan test, Brazilian splitting test, uniaxial and triaxial compression test were carried out on the sandstone under different dry and wet cycles. The experimental results show that under the same dry-wet cycle times n, the macro and meso-mechanical parameters of sandstone in "dry" state are larger than those in "saturated" state. The mean value of CT number in each typical region increases with the nonlinear accumulation of cycle number and changes rapidly at the initial stage. When n 鈮，
本文编号：2353370
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