利用CT扫描研究干湿循环泥岩软化过程

Study on mudstone softening process in drying-watering cycles by using CT scan

对岩石遇水后力学性质的变化规律的研究,是水岩相互作用研究中一个重要的方向。通过对四组泥岩试样的干湿循环试验设计、力学性质测试和CT扫描裂缝统计试验,重点讨论了泥岩强度损伤的机制。研究发现:随着干湿循环次数的增加泥岩试样的强度损伤依次递增,而在第Ⅰ循环阶段后损伤最为明显;利用CT扫描统计样品干湿循环裂缝,发现样品中裂缝面积呈现上升趋势,其中第Ⅰ循环阶段裂缝面积占总裂缝面积的50%;最后深入讨论试验结果,得到了泥岩样品在干湿循环后强度损伤的主要原因是由于样品中裂缝的大面积产生,而首次遇水导致裂缝快速发育也是第Ⅰ干湿循环阶段后强度损失的主要原因。

The study on the changing rules of the mechanical properties of rocks under water is an important aspect in water-rock interaction study. Through the four groups of shale specimens under the drying and watering cycle testing, the mechanical property testing and the CT scanning fracture statistical testing, the mechanism of mudstone strength loss is mainly discussed. The studies show that with the increase of the drying-watering cycle times the strength losses of the shale samples increase, and the loss is the most obvious after the Ⅰ cycle; based on the drying-watering cycles and the CT scan statistic samples it is found that the areas of the sample cracks increase, among them the first time Ⅰ loop fracture area is about 50% of the total crack area; after discussing the test results of mudstone samples the main reason of the drying-watering cycle strength loss is because of the large-area fractures, and for the first time watering leading to the rapid development of fractures is also the main reason of the strength loss after the dry-wet cycle Ⅰ.