Effect of volume change and boundary condition on desiccation crack network of compacted soils

Abstract

This report presents results of an experimental study on the desiccation of cracks in compacted soil with respect to volume change and boundary conditions imposed. The main experiments carried out to obtain the results were soil-water characteristic curve test and three desiccation tests with different soil thicknesses and boundary conditions.

It was found that there was a non-linear relationship between the number of cracks formed and the gravimetric water content, as well as, between the number of cracks formed and the matric suction.

In addition, the thickness of soil and boundary conditions did not affect the time when cracks were first formed.

Results had shown that the soil with smaller soil thickness formed the most number of cracks which were shorter in length and had smaller crack apertures as compared to the soil with larger soil thickness.

Furthermore, the soil with smaller soil thickness and an oiled base as boundary condition formed the least number of cracks which had longest length and largest crack apertures.