千枚岩碎屑土三轴试验剪切带扩展性状的CT研究

发布时间：2019-06-04 12:32

【摘要】：土体剪切带的产生和发展是岩土工程界一直关注的问题。对千枚岩碎屑土进行了固结排水剪切试验,并在试验过程中采用CT可视化技术进行了实时监测扫描,得到同一断面位置不同应变条件下的系列CT切片,从CT切片中可观测到试样随应变的增加而出现的明显的剪切带。采用CT技术真实再现了三轴试样在轴向力作用下,局部裂纹扩展逐渐贯穿形成完整剪切带的过程。对CT切片进行了7个区域的CT数平均值和CT数标准差统计,分析认为,轴向应变在3%~10%范围内是剪切带形成和发展的主要阶段,在应变3%前试样主要被压缩,在应变3%后试样在偏应力的作用下逐渐出现微裂隙,并随应变的增加,微裂隙越来越明显。CT数统计值出现微裂隙的应变和宏观观测到微裂隙的应变不对等,在判断剪切带微裂隙出现应变上建议以CT数统计值为准值。
[Abstract]:The generation and development of soil shear zone has been concerned by geotechnical engineering. The consolidation drainage shear test of thousands of rock clastic soils was carried out, and the real-time monitoring and scanning was carried out by using CT visualization technology, and a series of CT slices under different strain conditions in the same section position were obtained. The obvious shear band of the sample with the increase of strain can be observed from the CT slice. CT technique is used to reproduce the process of local crack propagation through the formation of complete shear band in triaxial specimens under axial force. The average value of CT number and the standard deviation of CT number in seven regions of CT slices are counted. It is considered that the axial strain in the range of 3% 鈮，

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