Image Analysis for the Quantification of a Developing Crack Network on a Drying Soil

Abstract The paper presents a methodology for quantifying surface crack patterns that appear in cohesive soils under drying conditions due to environmental changes, using image analysis techniques. This has practical applications in the study of many geotechnical problems related to soil cracking such as the impact of permeability changes due to cracking in clay barriers, development of preferential flow paths for contaminant transport along cracks, decreasing bearing capacity, and others. The study of soil cracking may become even more relevant with the current climate change that may induce more frequent and severe droughts in many parts of the world, increasing the areas at risk of cracking. Qualitative and quantitative characterization of the crack patterns is needed to study the mechanical behavior of a cracking soil, how cracks generate and propagate. For this purpose a simple laboratory set-up has been developed for continuous monitoring of the processes of formation and propagation of cracks due to desiccation, and to study the final crack pattern. The paper describes a simple technique to process sequences of images obtained during the laboratory tests, and how image analysis can be used to quantify the parameters that characterize the evolving and final crack patterns.