Study on the Progressive Failure Characteristics of Longmaxi Shale under Uniaxial Compression Conditions by X-ray Micro-Computed Tomography
Study on the Progressive Failure Characteristics of Longmaxi Shale under Uniaxial Compression Conditions by X-ray Micro-Computed Tomography
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DOI：
10.3390/en10030303
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发表时间：
2017-03-01
期刊：
影响因子：
3.2
通讯作者：
Zhou, Runqing
中科院分区：
文献类型：
--
作者：
Li, Xiao;Duan, Yongting;Zhou, Runqing
为了从细观和宏观角度研究龙马溪页岩在单轴压缩条件下的变形破坏过程，采用新型X射线显微CT（micro-CT）设备和独特的加载装置。制备圆柱形页岩样品（直径为4 mm，高度为8 mm）以进行一系列单轴压缩试验。在加载过程中的不同时间点的CT扫描图像，以研究渐进破坏的特点。此外，重建立体图，并选择垂直切片来解释失效机制。从测试结果来看，在CT图像上连续出现低密度区、局部峰前裂纹、大量峰后裂纹和二次裂纹。从立体图的表面和内部切片可以观察到样品中的垂直和倾斜裂缝。页岩的开裂表明页岩的破坏过程是渐进的，单轴压缩下页岩的破坏机理主要是拉伸破坏或拉剪综合破坏。
To investigate the deformation-failure process of Longmaxi shale under uniaxial compression conditions from the mesoscopic and macroscopic points of view, novel X-ray micro-Computed Tomography (micro-CT) equipment combined with unique loading apparatus was used. Cylindrical shale samples (4 mm in diameter and 8 mm in height) were produced to perform a series of uniaxial compression tests. CT scanning images at different time points during the loading process were obtained to study the characteristics of the progressive failure. In addition, stereograms were reconstructed and vertical slices were selected to explain the failure mechanism. From the results of the testing the low-density area, local per-peak cracks, numerous post-peak cracks and secondary cracks consecutively appeared in the CT images. Vertical and inclined fissures in the samples could be observed from the stereograms' surfaces and from internal slices. The cracking indicates that the failure process of shale is progressive and the failure mechanism of shale under uniaxial compression is mainly tension destruction or comprehensive tension-shear destruction.