Empirical Correlation Between Geophysical and Geotechnical Parameters of Pleistocene Madhupur Clay in Dhaka, Bangladesh

Abstract

This study investigates the potential for correlating geophysical and geotechnical parameters of the Pleistocene Madhupur Clay formation in Dhaka, Bangladesh. Due to rapid urban expansion and infrastructure development, there is a growing need for efficient subsurface characterization. Traditional geotechnical methods, though reliable, are expensive and limited in spatial coverage. Geophysical methods such as Electrical Resistivity Tomography (ERT) and Multichannel Analysis of Surface Waves (MASW) offer non-invasive, cost-effective alternatives. Fifteen ERT and MASW surveys were conducted at key locations across Dhaka. Five Standard Penetration Test (SPT) boreholes were used for ground-truthing. Laboratory analysis of soil samples focused on moisture content, Atterberg limits, unit weight, unconfined compressive strength (UCS), and consolidation behavior. Regression analysis revealed strong correlations between resistivity and SPT-N values (R² = 0.69), resistivity and moisture content (R² = 0.74), shear wave velocity and unit weight (R² = 0.79), and Vs and UCS (R² = 0.64). These results support the use of ERT and MASW as effective proxies for estimating subsurface properties in complex urban environments dominated by Madhupur Clay.