Experimental and Numerical Study on Shrinkage and Cracking of Clay along Drying Path

The issue of clay shrinking and cracking during the drying process has become increasingly severe due to rising global temperatures and the growing frequency of extreme weather events. Considering that clay is a highly complex medium characterized by uncertainty, discontinuity, and randomness, identifying the intrinsic mechanisms of desiccation shrinkage and cracking of clay is quite challenging using both experimental and numerical approaches. The primary objective of this article is to achieve a more comprehensive understanding of the phenomena associated with shrinkage and cracking of clay along the drying path through a combination of numerical simulations and laboratory experiments. Experimental observations reveal that strain concentration areas are generated in clay due to the coupling of constrained boundary conditions and local water content gradients. If tensile strain in clay exceeds a defined fracture criterion before reaching its maximum value, cracks appear within the strain concentration zone under extension. A constitutive model describing desiccation shrinkage of clay was established. Strain-based criteria for crack initiation and propagation are proposed, taking into account the potential for observation. The extended finite element method (XFEM) is employed to numerically investigate desiccation cracking of clay. XFEM also reveals explanations related to the conditions under which cracks initiate, crack evolution mechanisms, and crack pattern characteristics. XFEM holds significant promise for investigating the origin and causes of soil cracks.