The influence of saturation on the cracking process in compacted desiccating clays

Bauhaus-Universität Weimar, Faculty of Civil Engineering, Chair of Geotechnical Engineering, 99423 Weimar Germany

^a Corresponding author: maria.noack@uni-weimar.de

Abstract

Tensile failure in unsaturated cohesive soils during desiccation is important for the design of geotechnical applications such as capping systems of landfills and sealing material of dikes. This study presents the results of different initial parameters of compacted clay samples such as gravimetric water content, dry density and degree of saturation. These parameters are varied systematically for each test to find the correlation between those parameters and the tensile failure. The tensile failure for all tests occurred by a comparable constant change of the degree of saturation. The soil specific saturation ratio S_r,s is defined as the quotient of saturation changes ΔS_r to initial saturation S_r,0. This parameter related to the total suction shows an equal course for all results. All in all, the course of the soil specific saturation ratio S_r,s is independent of all initial parameters. These results provide a physical and hydraulic-mechanical description for modelling the desiccation process. To demonstrate the initiation and progress of tensile failure, the experimental results are modelled with a Discrete Element Method (DEM) approach.