Morphological description of desiccation cracks in soils: insights from the perspective of anisotropy

作者：Dai, Bei-Bing; Yang, Jun; Liu, Feng-Tao^*; Tang, Chao-Sheng; Li, Tian-Qi

来源：Bulletin of Engineering Geology and the Environment, 2022, 81(3): 94.

DOI：10.1007/s10064-022-02600-7

• Soil layer
• Desiccation cracking
• Morphological description
• Anisotropy
• Container shape
• Vector quantity

The characterization of a soil crack network requires a comprehensive understanding of statistics and has been of longstanding interest but not well resolved. By performing a series of desiccation cracking tests with a soil mixture comprising fines and montmorillonite, we make a systematic examination of the effect of the container shape on the anisotropic distribution of a crack network. The statistical analyses show that the angular distributions of crack orientation and length vectors in the cases of square and rectangular shapes have the feature of orthogonal concentration in two angular zones near the horizontal and vertical directions (i.e., - 15 degrees < phi < 15 degrees and 75 degrees < phi < 105 degrees) and that a larger magnitude of anisotropy results in a more intense concentration around the principal direction of anisotropy, whereas the angular distributions of these two vectors are in an almost isotropic state for the circular shape. The angular distributions of crack width and area vectors do not have an orthogonal concentration for any container shape. The distributions of crack area vectors approximate to an isotropic state for the square and circular shapes and have weak anisotropy for the rectangular shapes, with the principal direction of anisotropy being near the vertical direction. It is revealed that either the crack length or width vector exercises a dominant influence on the angular distribution anisotropy of crack area vectors only if its angular distribution bears relatively strong anisotropy.

• 单位
  南京大学; 中山大学; 桂林理工大学