Application of electrical resistivity method in the characterization of 2D desiccation cracking process of clayey soil

Abstract

Electrical resistivity method (ERM) is an attractive approach in the assessment of soil physical properties (water content, void ratio, density, etc.), which are closely related to electrical resistivity distribution. ERM performance in the detecting and mapping of cracks initiation, propagation, and coalescence processes in the 2D/3D scale needs to be studied to provide the technical support for its field application. An evaporation test of a clayey soil specimen with an integrated experimental configuration is performed to analyze the performance of ERM in the characterization of the 2D desiccation cracking process. The evolutions of ambient temperature, relative humidity, average water content, crack morphology, and apparent electrical resistivity of the studied sample are well captured during continuous drying. Image processing allows the quantitative geometrical description of the crack pattern formation. The consistency between the start-to-increase point of measured electrical resistivity, electrical resistivity anomalies, and the cracks propagations presents the good performance of ERM in crack characterization and reveals its potential to map the cracks before possible visualization. A better understanding of the fundamental mechanisms of desiccation cracking is also obtained based on the experiment results. This study provides an insight to apply ERM for engineering purposes involving crack monitoring and early crack detection.