Modelling desiccation crack geometry evolution in clayey soils by analytical and numerical approaches

Abstract

In the present work, the development and geometry of desiccation cracks are studied by using a finite element code including cohesive joints elements. The numerical results show that cracking occurs sequentially to form different crack families. The propagation of each crack at the onset suddenly reaches an ultimate depth. The cracks in each family appear simultaneously and reach an identical ultimate depth. From the numerical results and additional analytical analysis, empirical correlations are proposed to predict the spacing and crack depth as a function of suction applied on the top surface, the soil parameters, and the desiccation rate. The proposed model shows that higher suction is required to initiate cracks at a higher value of soil tensile strength. In addition, there is a general trend of larger spacing and deeper cracks for a slower desiccation rate. Finally, empirical relations are evaluated by comparing them with in situ experimental observations published previously.