Geotechnical Properties of Foundation Subsoils in Parts of Port Harcourt City, Obio/Akpor and Ikwerre Local Government Area, Rivers State, Nigeria

Abstract

The study was carried out with the objectives of determining the stratification, geotechnical index properties of the soils in part of Port Harcourt city and Obio/Akpor local Government Area, Rivers state. Field Exploration and laboratory studies of soils samples were obtained from 0-20.25m deep. Subsurface soil profiles were delineated followed by determination of their index and mechanical properties, including Atterberg limits, particle sizes distribution, undrained shear strength, shear box test and consolidation coefficient. Results reveal an overlying light brown sandy clay, soft to firm consistency, clay thickness vary from 9.0 to 13.5m. Beneath this overburden lie yellowish brown to light grey fine to medium to coarse grained sand, loose to medium dense to dense consistency and poorly graded sand, thickness vary from 6.75 to 11.25m. The clays show low to intermediate clay plasticity (CL-CI). The shear strength parameters of these c- soil gave values range of 40-60KN/m2 . Allowable bearing capacities for the shallow foundation and bored pile foundation analysis was also carried out for the soil profiles with diameter 306, 406, 460 and 600mm for the deep foundation for various study areas were calculated.