不同含水状态砂岩分级循环荷载试验研究

发布时间：2018-06-25 19:47

本文选题：砂岩 + 含水率　；参考：《水文地质工程地质》2017年01期

【摘要】：为探究不同含水状态砂岩在循环荷载作用下的力学行为差异,对干燥、天然以及饱和三种含水状态下的砂岩进行了单轴分级循环加卸载试验。研究结果表明:由于水对砂岩的物理化学软化作用,饱水、天然以及干燥状态下的强度依次递减,而变形依次增加;卸载模量随着循环周次的增加呈先增大后减小的整体趋势,同一循环周次下,含水量越高,其卸载模量越小;体积应变开始出现拐点时的循环周次正好与卸载模量转折点所处的加卸载周次相对应;能量值随循环周次的增加均呈幂函数型增长,同一循环周次下,含水率越高的砂岩各项能量值越大;基于能量耗散的损伤定义表明:砂岩初始损伤值不为零,且均经历了一个先减小后增大的损伤演化过程,相同循环周次下,饱和、天然以及干燥砂岩的损伤量依次增大。
[Abstract]:In order to explore the difference in mechanical behavior of sandstone under the cyclic loading of different water bearing States, the uniaxial cyclic loading and unloading tests of sandstone under three kinds of dry, natural and saturated state of water are carried out. The results show that the strength of the sandstone under the condition of physical and chemical softening, full water, natural and dry state is successively recurring. The unloading modulus increases in turn, and the unloading modulus increases first and then decreases with the increase of cycle cycle. Under the same cycle, the higher the water content, the smaller the unloading modulus; the cycle times when the volume strain begins to turn on the turning point coincides with the unloading cycle at the turning point of the unloading modulus; the energy value follows the cycle cycle. In the same cycle, the higher the water content, the greater the energy value of sandstone, and the damage definition based on the energy dissipation shows that the initial damage value of sandstone is not zero, and the damage evolution process is reduced first and then increased, and the damage amount of saturated, natural and dry sandstone under the same cycle cycle. Increase in turn.
【作者单位】：兰州资源环境职业技术学院地质工程系;兰州大学土木工程与力学学院;
【基金】：国家重点基础研究发展计划(2014CB744701)
【分类号】：TU45

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