Desiccation of a sensitive clay: application of the model CRACK

Abstract

Field data obtained during the desiccation of an intact clay were used to assess the performance of a model enabling the prediction of depth and spacing of primary shrinkage cracks. The model requires several input parameters such as the soil-water characteristic curve to predict the evolution of the suction profile with time, the tensile strength of the soil to define the conditions at crack initiation, and the fracture toughness to calculate ultimate crack depth. Predictions of suctions at crack initiation, time of crack initiation, and depth of crack propagation were reasonable using laboratory determined values of these soil properties obtained from undisturbed samples. Field data suggest that neighbouring cracks form where the computed relief stresses reach 80 to 88% of the tensile strength of the soil.