Geoelectrical Investigation of Soils as Foundation Materials in Umudike Area, Southeastern Nigeria

Geoelectrical investigation of soils in Umudike area of Abia State was undertaken in order to determine the competence of the soils as foundation materials. A total of 18 Vertical Electrical Sounding (VES), using Schlumberger configuration was carried out. The results revealed three to six distinct geoelectric sequences with resistivities ranging from about 8 Ωm to about 38,000 Ωm and a variation in topsoil thicknesses with the least as 0.2 m at vicinity of VES Station 2 Ahiaeke and the highest as 5.0 m at VES Station 14 MOUAU. The topsoils are composed of sands, silts, sandy clays, clays and laterites. The study also revealed the cause of frequent cracking and collapse of a portion of the Umuahia-Ikot-Ekpene road. Based on the results of the survey, the most competent soils within which large civil engineering structures will be founded within the study area are encountered at VES 8,9 (inside ABSUPAC), 6 (opposite GCU), 14 and 15 ( inside MOUAU).