Monitoring and mapping the evolution of clayey soil desiccation cracking using electrical resistivity tomography

Drought-induced clayey soil desiccation cracking is a common natural phenomenon. The presence of cracks can significantly alter the mechanical and hydraulic properties of clayey soils, and cause a series of engineering problems or hazards. Electrical resistivity tomography (ERT) is a sensitive and non-destructive technique capable of imaging the spatiotemporal resistivity variations in cracked soil. This study presents a novel ERT-based method integrating numerical modeling and experimental test to characterize the cracking morphology and quantify the cracking depth. Soil images synchronously taken record the crack morphology in the soil body during drying. Experimental results indicate the desiccation cracking patterns can be effectively reflected by the measured electrical resistance curves, implying that ERT can capture the subsurface soil cracking process. The relative variation rate of resistivity improves the accuracy of ERT in imaging the crack morphology. Furthermore, the cracking depths estimated using ERT are consistent with experimental observation. This study is expected to introduce a scheme based on ERT for monitoring the real-time evolution of clayey soil desiccation cracking and provide insights on managing and controlling the stability and performance of earth structures.