Geoenvironmental Evaluation and Characterization of Near-Surface Subsoils for Sustainable Building Construction: An Integrated Approach

Geoelectrical resistivity imaging was integrated with cone penetrating test (CPT) and standard penetrating test (SPT) for a preliminary investigation for building construction in a foreshore environment of Ilubirin Lagos, Nigeria. The two-dimensional electrical imaging revealed two inferred geoelectrical layers of loose silty sand (80.0–400 \(\Omega {\text{m}}\)) and sandy clay (2.66–50.0 \(\Omega {\text{m}}\)). An average CPT value of 10–48 km/cm² was measured between 0.5 and 7 m. The submerged bearing pressure ranged from 8 to 65 kN/m². Generally, geotechnical investigations revealed the subsoils characteristics to range from soft to firm clay with low to moderate shear strength. It is recommended that a deeper pile foundation type should be adopted in the construction site so that the building would transmit their loads to a more stable basal subsoil stratum within the subsurface.