97 / 2019-07-31 23:36:15

Mechanisms of crack initiation and propagation in clayey loess related to desiccation using a correlation image method

Clayey loess; field investigation; laboratory tests; digital image correlation;

水库地质灾害防治与生态环境保护 > 表生地质作用与地质灾害演化过程

The Chinese Loess Plateau is located in northwestern China. During investigation of loess fields, it was found that under dry climatic conditions, cracks are prone to appear and propagate in the loess plateau. The objective of this research was to analyze the characteristics of cracks and the cracking mechanisms in loess related to desiccation. Besides field investigation, laboratory tests were performed to simulate the cracking process in loess. The local strain tensors in loess during drying, as well as the cracking phenomenon, were determined using Digital Image Correlation method. The method was based on the determination of the local two-dimensional strain and displacement fields using the program Vic-2D. Different mechanisms of crack formation were identified: modes of cracks, including opening and sliding modes, bifurcation and coalescence of cracks. At the end of desiccation, the cracks formed a network. This study highlights the mechanics of cracks.