Prediction of desiccation crack depths allowing for shear failure

Desiccation cracking is a major issue in many geotechnical applications, especially in the applications such as in landfill clay liners and in dam embankments comprising clay soils. In this regard, it is important to be able to predict the possibility of desiccation cracking within the geo-structure. The depth of cracking is a crucial parameter that needs to be examined in order to understand the effects of desiccation cracks and hence the long-term performance of clay soils. Researchers have developed various methods to compute the likely depth of desiccation cracking using various theoretical assumptions. This paper presents a summary of existing analytical methods that can be used to calculate the depth of cracking. It extends this work to a more elaborate numerical model that can be used to predict the depth of desiccation cracking allowing for the possibility of soil shear failure. This numerical analysis was conducted using the computer program UDEC, which is a hybrid continuum/distinct element program. The results from the numerical approach are compared with theoretical results, highlighting the applicability of the current approaches.