灰岩岩样等幅和分级循环加卸载过程中电阻率响应规律研究

发布时间：2018-05-19 22:20

本文选题：岩石力学 + 等幅循环加卸载　；参考：《岩石力学与工程学报》2015年S2期

【摘要】：为研究受载过程中特别是循环加卸载作用下岩石电阻率变化规律,对单轴等幅循环加卸载和分级循环加卸载条件下岩石破坏过程中的电阻率响应特征进行研究。试验结果表明,岩石电阻率变化与荷载变化或试件内微裂隙发展密切相关。等幅循环加卸载过程中,加载时随着荷载的增加,岩石的电阻率总体上呈下降的变化趋势;第1次加载循环与其他4次加载循环明显不同,在加载初期存在快速下降阶段;卸载时,试样电阻率会逐渐恢复;5次加载循环中,完全卸载(载荷0 k N)和完全加载(载荷40 k N)时,不同循环电阻率不同,第一次最大,以后逐次减小。分级循环加卸载与等幅循环加卸载存在一些相同的规律,不同之处在于:5次加载循环中,完全卸载(载荷0 k N)和完全加载(载荷取第一级完全加载时荷载35 k N)时,不同循环电阻率也不同,前3次循环电阻率依次减小,后2次循环逐次略有增加;破坏加载时,加载初期也存在快速下降阶段。对2种循环加卸载过程中电阻率变化规律采用循环加载下微裂隙闭合机制进行了解释。试验研究表明,电阻率变化可以较好地表征单轴等幅循环加卸载和分级循环加卸载过程中试件内微裂隙发展情况。
[Abstract]:In order to study the variation of rock resistivity during loading, especially under cyclic loading and unloading, the characteristics of resistivity response during rock failure under uniaxial cyclic loading and unloading and graded cyclic loading and unloading are studied. The results show that the change of rock resistivity is closely related to the change of load or the development of microcracks in the specimen. In the loading and unloading process of constant amplitude cyclic loading, the resistivity of rock decreases with the increase of load, and the first loading cycle is obviously different from the other four cycles, and there is a rapid decline stage in the initial loading stage. At unloading, the resistivity of the specimen will gradually recover in the five cycles. When the load is completely unloaded (load 0 K N) and full load (load 40 K N), the resistivity of different cycles is different, the first time is the maximum, and the later gradually decreases. There are some same laws between graded cyclic loading and unloading with equal amplitude cyclic loading. The difference lies in the complete unloading (load 0 K N) and complete loading (load 35 K N) in the 5 times loading cycle. The resistivity of the first three cycles decreases in turn, and the latter two cycles increase slightly, and there is a rapid decline stage in the early stage of loading. The variation of resistivity during cyclic loading and unloading is explained by microfracture closure mechanism under cyclic loading. The experimental results show that the variation of resistivity can well characterize the development of microcracks in the specimens during the loading and unloading of uniaxial cyclic loading and unloading with equal amplitude and the loading and unloading process of graded cycles.
【作者单位】：山东大学岩土与结构工程研究中心;
【基金】：国家重点基础研究发展计划(973计划)项目2013CB036002,2015CB058101) 国家重大仪器设备研制专项(51327802))
【分类号】：TU45

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