Canadian Journal of Pure & Applied Sciences

Abstract: This paper presents an investigation on the properties of soils underlying the permanent site of the Nnamdi Azikiwe University, Awka, Nigeria. A total of 450 samples collected from 150 Hand auger drilled holes across the campus were subjected to different geotechnical tests. Geotechnical parameters tested for in the soil samples were mechanical analysis, Atterberg limits, compaction, CBR, bulk density, natural moisture content and shear strength. Results indicated that the soils consisted of predominantly sand-sized grains overburden (either SM or SC); percentage of fines ranged from 7 to 72%, sand 28 to 93% and gravel 0 to 40 %. Liquid limit values ranged from minimum value of 15 (at depth 0 to 1.5m) to maximum value of 78 (at depth ?1.6m), while Plasticity index values ranged from non-plastic samples to a maximum value of 41. Plots of samples in the plasticity chart revealed the fines are predominantly clays and silts of low plasticity (CL - ML), and less amount of organic silts (MH or OH). Medium to high plasticity resulting from moderate to high clay content of the soil suggests volumetric changes, especially when the site is waterlogged. The bearing capacity and settlement (in particular compressibility) analyses confirmed that most locations within the site have low stability. A number of sampled points have their compression index values above 0.20, suggesting that those points would experience moderate compressibility over engineering time.