Cracking in drying soils

TLDR

Soil drying cracks are governed by soil suction and mechanical properties such as compression modulus, Poisson's ratio, shear and tensile strength, and specific surface energy. The study reviews crack occurrence and morphology in dry‑climate Australia and Canada. After reviewing unsaturated soil behavior and cracking mechanics, the authors develop solutions based on elasticity theory, the transition between tensile and shear failure, and linear elastic fracture mechanics, and compare these solutions to field‑observed crack depths. Keywords: clay, cracks, crust, shear strength, soil suction, tensile strength, unsaturated soil, weathering.

Abstract

Cracking in soils that are undergoing drying is controlled by soil suctions and by soil properties such as compression modulus, Poisson's ratio, shear strength, tensile strength, and specific surface energy. The paper reviews the occurrence and morphology of cracks in dry-climate regions of Australia and Canada. After reviewing the behaviour of unsaturated soils and the mechanics of cracking, solutions are developed based on (i) elasticity theory, (ii) the transition between tensile and shear failure, and (iii) linear elastic fracture mechanics. The solutions are compared and related to crack depths observed in the field. Key words : clay, cracks, crust, shear strength, soil suction, tensile strength, unsaturated soil, weathering.