Multiscale Laboratory Study and Numerical Analysis of Water-Weakening Effect on Shale
Multiscale Laboratory Study and Numerical Analysis of Water-Weakening Effect on Shale
复制标题
页岩弱水效应多尺度室内研究及数值分析
DOI：
10.1155/2020/5263431
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发表时间：
2020
影响因子：
--
通讯作者：
Dun Zhilin
中科院分区：
文献类型：
--
作者：
Li Zhen;Liu Shangge;Ren Wentao;Fang Jinjin;Zhu Qinghua;Dun Zhilin
水的弱化效应是导致黄家寨隧道页岩大变形和稳定性问题的重要因素之一。水对不同含水率页岩的影响及其机理还有待进一步研究。本文首先通过X射线衍射法和吸水率实验确定了矿物组成对水-岩相互作用的影响。在此基础上，对页岩进行了单轴压缩试验、巴西圆盘试验和三轴压缩试验，分别在干燥条件、不同含水率的润湿条件和饱和条件下进行了岩石力学试验。对于单轴压缩、拉伸和三轴压缩，软化系数可分别达到0.38、0.63和0.52。在宏观试验的基础上，对隧道开挖过程中的水效应进行了数值研究。最后，借助扫描电子显微镜和破坏形态，从微观和宏观两个角度探讨了页岩水弱化作用的机理。双层膜的厚度随着浸水时间的增加而增加。本文为页岩地层施工提供了一组有用的数据供参考，并提供了一种通过实验室和数值模拟方法来评价弱水效果的方法。
Water-weakening effect is one of the most important factors inducing large deformation and stability problems of shale strata in the Huangjiazhai Tunnel. The influence of water on shale with various water contents and its mechanism still needs more study. In this paper, the X-ray diffraction and water absorption test were first conducted to determine the influence of mineral components on water-rock interaction. Then, a series of rock mechanical tests, including uniaxial compressive test, Brazilian disk test, and triaxial compressive test, were carried out on shale under dried condition, wetted condition with various water contents, and saturated condition. For the uniaxial compression, tension, and triaxial compression, the softening coefficient could reach 0.38, 0.63, and 0.52, respectively. Based on the macroscale experiments, a numerical case study of tunnel excavation was investigated to evaluate the water effect. Finally, with the aid of scanning electron microscope and failure morphology, the mechanism of water-weakening effect on shale was discussed from microscopic and macroscopic perspectives. The thickness of the double layer increases with the increase of water immersion time. This paper provides a set of useful data for reference in construction in shale strata, and a methodology to evaluate water-weakening effect through laboratory and numerical modelling approaches.