Integration of Vertical Electric Sounding (VES) and Standard Penetration Test (SPT) for Geotechnical Investigation of Subsurface in Phuket

Abstract

For geotechnical investigation, the electrical resistivity method (ERM) and conventional methods have been accepted. There has been a growing interest in the integration of ERM and conventional methods. Phuket is a popular tourist destination, and the island's rapid infrastructure development is causing growing concern. The purpose of this research is to determine the relationship between electrical resistivity using ERM and geotechnical parameters for sand layers in Phuket, including SPT data, corrected N-value, and estimated geotechnical parameters (share wave velocity, friction angle, young's modulus, and relative density). In addition, data were classified continuously based on geological and seasonal classifications. Using the Pearson correlation method, this study analyzed the relationship between electrical resistivity using ERM and geotechnical data. This study investigated the model function for estimating geotechnical parameters from electrical resistivity using the least square method. Electrical resistivity was found to be correlated with geotechnical parameters on sedimentary and metamorphic rocks during the same seasons of SPT and VES deployments for sand layers in Phuket. Electrical resistivity and geotechnical parameters have a moderate, negative, and statistically significant relationship. Thus, as an indirect predictor of geotechnical parameters, electrical resistivity using ERM is significant. The correlation between ERM and conventional methods may be affected by geology and seasons. ERM is discovered to be a useful tool for estimating geotechnical parameters in geotechnical investigations of subsurface sand layers in Phuket.