Geotechnical tests were carried out on a total of six samples of red tropical soils developed over sedimentary and Basement terrains, made up of three soils and three termite hills samples. The soil samples were subjected to geotechnical analyses which included the Particle size analysis, Specific Gravity, Atterberg Limits and Compaction Test to evaluate their suitability for road construction. The results from the analyses showed that soils were well graded(GW) with percentage fines ranging from 28.06 to 57.8%, Specific Gravity ranged from 2.40-2.60, Liquid Limit from 36-48.5% , Plastic Limit ranged from 19-30% , Plasticity Index 15-19% and California Bearing Ratio(unsoaked) from 11-24%. For the termite soils Liquid Limit varies from 26.5-33%, Plastic Limit 19-23%, Plasticity Index 10-12% and California Bearing Ratio 24-40%. The Compaction Test results showed that the Maximum Dry Density (MDD) ranged from 1.44 to 1.65%, 1.6-1.8% and Optimum Moisture Content from 16.3 to 23.8% and 12.5 to 17.8% for soils and termite hill respectively. From the results of the analyses and in accordance with the Federal Ministry of Works and Housing, recommendations for road base, subbase and subgrade, both soils can be used for road construction as subgrade but the termite hill of Igarra indicate a better material because of its higher strength with higher MDD to low moisture content.

A geophysical survey of the University of Benin was carried out using the resistivity method for groundwater investigation. Five (5) vertical electrical sounding (VES) points were taken to ascertain the groundwater availability and depth to groundwater in the area. Areas recording low resistivities had a likelihood of being water bearing and so data collected was interpreted. The VES data indicated that between 5 to 7 layers of soil were encountered ranging from the topsoil to the aquiferous layer. The depths ranged between 106ft to 209ft. The flow direction and depth to water table models generated indicate a lower elevation around the central area and points located around this area would have a higher possibility of a high water yield.

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With the increasing rate of infrastructural development within developing Africa and the increase in failure of construction materials, there is need to seek solutions to further improve on the quality of materials used. Soils from anthills have been studied to possess some improved geotechnical properties that may improve the quality of materials used for construction, especially road construction. Soils from anthills were collected from different parts of Edo State, southwest Nigeria and was subjected to some geotechnical tests -Atterberg, compaction, CBR and particle size teststo ascertain the properties of the soils. The uniformity coefficient and coefficient curvature of the soils indicated that they are good subgrade materials for road construction. This can also be confirmed by the percentage fines of above 28% for all samples, plasticity index of above 10, optimum moisture content of above 12% and maximum dry density of 1.65 and above. Values from the soaked and unsoaked CBR tests also conforms with that of a good subgrade material when compared with the USCS and AASHTO classification