The study investigate the suitability of subgrade soil in Baure Local Government Area of Kastina State Nigeria for road construction. The strength properties of the  subgrade was improved using lime and cement. Several analysis including the particle size distribution, specific gravity, Atterberg limits, compaction characteristics, unconfined compressive strength and California bearing ratio tests were performed on natural and lime/cement treated soil samples in accordance with BS 1377 (1990) and BS 1924 (1990) respectively. Soil specimens were prepared by mixing the soil with lime and cement in steps of 0, 3, 6, and 9% by weight of dry soil in several percentage combinations. The Atterberg limits of the weak subgrade soils improved having a minimum plasticity index value of 5.70 % at 3%Lime/6%Cement contents. The maximum dry density (MDD) values obtained showed a significant improvement having a peak value of 1.66 kN/m3 at 9%Lime/9%Cement contents. Similarly, a minimum value of 18.50 % was observed for optimum moisture content at 9%Lime/9%Cement contents which is a desirable reduction from a value of 25.00 % for the natural soil. The unconfined compressive test value increased from 167.30 kN/m2 for the natural soil to 446.77 kN/m2 at 9%Lime/9%Cement contents 28 days curing period. Likewise, the soaked California bearing ratio values increased from 2.90 % for the natural soil to 83.90 % at 9%Lime/9%Cement contents. Generally, there were improvements in the engineering properties of the weak subgrade soil when treated with lime and cement. However, the peak UCS value of 446.77 kN/m2 fails to meet the recommended UCS value of 1710 KN/m2 specified by TRRL (1977) as a criterion for adequate stabilization using Ordinary Portland Cement.            Keywords: Weak subgrade soil, Lime, Cement, Atterberg limits, Maximum dry density, Optimum moisture content, Unconfined compressive strength, California bearing ratio

Geophysical investigation of the permanent site of Federal University, Dutsin-Ma located in Katsina State site was carried out with the objective of investigating the subsoil conditions based on geophysical site exploration methodology in order to take precise engineering decisions on the best locations for different utilities and ground water profile establishment. The major instruments used in carrying out the fieldwork include: SAS 300, Reels of cables, sets of electrode, hammer, tapes and sealed battery. Six survey profiles were used with 200m length each. Dedicated geophysical software was used for the data processing. Results show that the thickness of the overburden which ranges between 2 m to 35 m is more in the southern part of the survey area than the northern part that has thin overburden thickness. This suggests that the thickness of the underground water aquifer will be more in the southern part of the survey area. Best locations of boreholes were recommended and alternative source of water was suggested based on observation.Keywords: Fresh basement, Geophysics, Resistivity imaging, Site investigation, Subsoil exploration, Aquifer

This study was carried out to investigate and determine the geotechnical parameters required for adequate design and positioning of structures and facilities of the proposed Minna City Centre, at Minna the capital of Niger state. The soil samples used for the study were obtained from 10 SPT boreholes at 0.6, 2.1 and 3.6 m depths and all laboratory tests were conducted in accordance with BS 1377. Results show that soil particle sizes increases with boring depth up to the basement complex and values of cohesion and angle of internal friction show that the shearing resistance and bearing capacity of soils will be relatively high and favourable for the intended structures. Average allowable bearing capacity values in the range of 100 – 300 kN/m2 are recommended for use in the study area with embedment depth between 1 – 3 m.