62 / 2025-04-24 12:55:29

Geoelectric Measurements of Internally Unstable Soils

Internally unstable soil, specifically underfilled gap-graded soil are prone to suffusion, a
mechanism of internal erosion where fine particles migrate under hydraulic flow. Over time,
suffusion results in the gradual washout of finer particles, which can ultimately lead to structural
failure. Conventional techniques for suffusion assessment rely on laboratory-based stability
criteria, which are effective but invasive and does not provide real time monitoring. This study
explores the potential of geoelectric measurements as a non-invasive alternative to identify
internally unstable soil and differentiate between underfilled and overfilled fabric. Direct Current
(DC) resistivity measurements were conducted on sand-gravel mixtures with 20% and 40% finer
fraction. Two key geoelectric parameters, formation factor and surface conductivity, were
calculated. These parameters are essential for understanding the electrical properties of the soil
mixtures and were correlated to conventional soil parameters. The results showed that geoelectric
parameters can effectively differentiate between underfilled and overfilled fabric. Moreover, the
findings exhibit a high degree of repeatability, indicating reliable measurements. These results
provide a solid foundation for the potential application of geoelectric measurements as a non
invasive method for monitoring suffusion.