World Journal of Engineering Research and Technology

Teme S. C. and Nwankwoala H. O.*

ABSTRACT

This study aims at assessing the sub-soil condition for design of foundation systems at the Federal University, Otuoke, Bayelsa State, Nigeria. A total of eighteen (18) soil borings employing the standard penetration testing (SPT) each to a depth of 30.0m and twenty nine (29) shallow borings (3.00 m deep) were made at pre-selected positions across the entire area of the Federal University, Otuoke, Bayelsa State. On the basis of field investigations and laboratory testing carried out on the soil samples obtained from the project site, it is observed that five (5) identifiable soil horizons are present and this are namely: Brownish clayey layer (CL) - [top soil], greyish organic silty clays (OL), greyish clayey silty sands (SM) and (SC-SM), yellowish to whitish silty sands (SM) and well-graded sands and gravels (SW). The obtained value for the bearing capacity for continuous strip footings to be used at the Project Site is about 153.35 + 1.483B [kPa] where B = width of the structure to be built. For a B = 5.00 meters, the bearing capacity was been found to be 160.76 kPa. The recommended depth of emplacement of continuous strip footings is 0.75 meters. This value represents the bearing capacity of the upper bearing lateritic clays and silty-clays at the project site. The range of values obtained for the bearing capacity for raft footings at the project site, based on the conventional SPT Method is between 76.55 and 208.86 kPa with an average of 122.85 kPa. The recommended depth of emplacement of raft footings is 1.50 meters. This value represents the bearing capacity of the upper bearing lateritic clays and silty-clays at the project site. Since the buildings at the University Campus may subjected to live loads from the movements of different numbers of students in a continuously day-to-day fashion over the years, the potentials of the silty soils becoming liquefied as a result of human traffic-induced vibration was also assessed during this study, since this is a permanent structure for ages to come. Soil dynamics analysis carried out indicate that there will be no possibility of Soil Liquefaction at the site as a result of vibration from the Gas Plant. This was found not to be possible even though the groundwater table was found near the ground surface because of the absence of totally silty soils beneath the ground surface.

[Full Text Article] [Download Certificate]