干湿循环作用下砂岩的劣化及破坏特性研究

发布时间：2018-09-03 11:08

【摘要】：针对干湿循环作用下消落带砂岩岩体强度衰减易导致砂岩边坡失稳的问题,以三峡库区秭归县沙镇溪典型库岸边坡砂岩试样为研究对象,采用浸泡—烘干处理方式模拟岩石干湿循环过程,将试样分组进行单轴压缩试验和直接剪切试验研究,并通过数值模拟,从变形的角度分析破坏过程。结果表明:干湿循环对砂岩的劣化作用在初期表现强烈,随着循环次数增加,作用逐渐减弱;在相同循环条件下,砂岩的极限抗剪强度随法向应力的增大而增加,相同法向应力作用下砂岩极限抗剪强度随干湿循环次数的增加而减小;粘聚力和内摩擦角随着干湿循环次数的增加而逐渐减小,总劣化度逐渐增大。试验结果对水库砂岩边坡稳定性分析具有较强的参考价值。
[Abstract]:In view of the problem that the strength attenuation of sandstone rock mass in the drop zone easily leads to the instability of sandstone slope under the action of dry and wet circulation, the sandstone sample on the bank slope of Shazhen River typical reservoir in Zigui County, three Gorges Reservoir area, is taken as the research object. The dry and wet cycling process of rock was simulated by soaking and drying. The specimens were divided into two groups: uniaxial compression test and direct shear test. The failure process was analyzed from the point of view of deformation by numerical simulation. The results show that the degradation of sandstone by dry and wet cycles is strong in the initial stage, and decreases gradually with the increase of cycle times, and the ultimate shear strength of sandstone increases with the increase of normal stress under the same cycle conditions. Under the same normal stress, the ultimate shear strength of sandstone decreases with the increase of the number of dry and wet cycles, the cohesion and the angle of internal friction decrease with the increase of the times of dry and wet cycles, and the total deterioration degree increases gradually. The test results have a strong reference value for the stability analysis of reservoir sandstone slope.
【作者单位】：三峡大学三峡库区地质灾害教育部重点实验室;中建三局第一建设工程有限责任公司;
【基金】：国家自然科学基金重点项目(51439003);国家自然科学基金项目(51679128) 水利部公益性行业科研专项经费项目(201401029) 2016三峡大学研究生科研创新基金(SDYC2016016)
【分类号】：TV223

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