NMR, MRI and AE Statistical Study of Damage due to a Low Number of Wetting–Drying Cycles in Sandstone from the Three Gorges Reservoir Area
NMR, MRI and AE Statistical Study of Damage due to a Low Number of Wetting–Drying Cycles in Sandstone from the Three Gorges Reservoir Area
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DOI：
10.1007/s00603-018-1562-6
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发表时间：
2018-08
影响因子：
6.2
通讯作者：
Kainan Xie;D. Jiang;Zhongguang Sun;Jie Chen;Wengang Zhang;Xiang Jiang
中科院分区：
文献类型：
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作者：
Kainan Xie;D. Jiang;Zhongguang Sun;Jie Chen;Wengang Zhang;Xiang Jiang
在隧道施工、采矿和大坝基础建设等许多工程领域，循环干湿对岩石材料的劣化起着重要作用（Wu等人，2005; Wang等人，2014）。干湿循环效应的典型例子可以在世界上最大的水力发电设施三峡水库中找到（见图1）。三峡水库的平均水位波动约30米（从145米到175米）。许多研究表明，水库蓄水后，由于干湿循环的影响，砂岩岸坡的稳定性降低（Chai等，2009; Jiang等，2012）。三峡水库库岸边坡总长5300 km，约有10%（约500 km）的边坡稳定性较差。较低数量的干湿循环会影响储层的机械性能。从2008年8月（水位首次达到175米）到2011年3月，三峡水库地质灾害比以往急剧增加。在此期间，共发生地质灾害378处，滑坡崩塌总量约3.2亿立方米，崩岸总长度约25.1公里，紧急转移群众10,482人。因此，有必要研究和评价低次数干湿循环对该区砂岩的影响。许多研究人员在物理和力学研究中研究了循环干湿对岩石材料的影响（Okluk 2014; Khanlari和Abdilor 2015; Vales等人2004）。然而，循环干湿过程仍然是岩石风化过程中知之甚少的组成部分（Zhao等人，2017）。在本文中，我们介绍了低场核磁共振（NMR）作为一种合适的方法来研究砂岩的干湿效应，
Cyclic wetting–drying plays an important role in the deterioration of rock materials in many engineering fields, such as tunnelling, mining, and dam foundation construction (Wu et al. 2005; Wang et al. 2014). Typical examples of the effects of wetting–drying cycle can be found at the Three Gorges Reservoir (see Fig. 1), which is the world’s largest hydroelectric power facility. The average water level in the Three Gorges Reservoir fluctuates by approximately 30 m (from 145 to 175 m). Many studies have shown that the stability of the sandstone bank slope was reduced after reservoir impoundment due to the impact of wetting–drying cycles (Chai et al. 2009; Jiang et al. 2012). The total length of the bank slopes in the Three Gorges Reservoir is 5300 km, and approximately 10%(approximately 500 km) of these slopes have low stability. A low number of wetting–drying cycles would affect the mechanical properties of a reservoir. From just August 2008 (when the water level reached 175 m for the first time) to March 2011, geologic hazards in Three Gorges Reservoir increased more drastically than before. During this period, 378 geological hazards happened; the total volume of landsliding and collapse was approximately 320 million cubic metres, the total length of bank collapse was approximately 25.1 km, and 10,482 people were urgently moved out of the area. Therefore, it is necessary to study and evaluate the effects of a low number of wetting–drying cycles on sandstone in this area. The influence of cyclic wetting–drying on rock materials has been investigated by many researchers in physical and mechanical studies (Ozbek 2014; Khanlari and Abdilor 2015; Vales et al. 2004). However, the cyclic wetting–drying process remains a poorly understood component of the rock weathering process (Zhao et al. 2017). In this note, we introduce low-field NMR (nuclear magnetic resonance) as one suitable method to study the wetting–drying effect on sandstone, as