Electrical Resistivity as a Supplementary Site Characterisation Tool Within an Integrated Geotechnical Investigation Framework for Calcareous Desert Deposits

Calcareous desert deposits present significant challenges for geotechnical site characterisation because of their heterogeneous composition, variable carbonate cementation, and complex mechanical behaviour. This study investigates the practical engineering value of electrical resistivity as a supplementary site characterisation tool within an integrated geotechnical investigation framework at the Shagaya area , Kuwait. An integrated geotechnical–geophysical investigation was conducted to evaluate the engineering significance of electrical resistivity in characterising heterogeneous calcareous desert deposits. The results indicate that the site is predominantly underlain by medium-dense to very dense calcareous sandy deposits exhibiting substantial variability in density, fines content, carbonate cementation, penetration resistance, and foundation stiffness. Standard penetration test (SPT) N-values ranged from 10 to 84, CPT cone resistance values ranged from 15 to 27.5 MPa, and PLT-derived modulus of subgrade reaction (Ks) values ranged from 24.3 to 210.3 MN/m³, demonstrating considerable spatial variability in engineering behaviour. Electrical resistivity values ranged from 57.2 to 271.9 Ω·m and consistently reflected variations in density, carbonate cementation, and foundation stiffness identified from conventional geotechnical testing. Higher resistivity values generally corresponded to denser, more strongly cemented deposits, whereas lower values were associated with finer-grained or less cemented materials. Unlike previous studies that focused on developing empirical resistivity-based correlations, this research evaluates electrical resistivity as a complementary investigation tool integrated with conventional geotechnical methods. Rather than developing site-specific predictive relationships, resistivity measurements were interpreted alongside borehole, laboratory, SPT, CPT, and PLT data to improve the understanding of subsurface variability. Instead, resistivity measurements are interpreted alongside borehole, laboratory, SPT, CPT, and PLT data to improve the understanding of subsurface variability and support engineering judgement. The proposed integrated geotechnical–geophysical framework enhances site characterisation, reduces uncertainty, and provides practical guidance for foundation investigations in heterogeneous calcareous deposits and large-scale renewable energy infrastructure projects in arid environments.