ASSESSMENT OF GEOTECHNICAL PROPERTIES OF SELECTED LATERITIC SOIL AS FILL MATERIALS FOR EARTH DAM CONSTRUCTION

Abstract

This study presents assessment of geotechnical properties of selected lateritic soil as fill materials for earth dam construction. Standard tests were carried out on 27 lateritic soil samples collected from selected borrowed pits in Maikunkele, Pyata and Lapai Gwari. The three locations are all in the surbubs of Minna. Niger State. Particle size analysis revealed that ten of the lateritic samples were gap-graded, while six were poorly graded. The compaction characteristics; MDD ranged between 1.65 to 1.99 g/cm3, with the OMC range of 9.8 – 21.2%. The hydraulic conductivity (k) ranged from 10-5 cm/s to 10-9 cm/s. The work further revealed average values of confined compressive strength (CCS), Cohesion (C), angle of internal friction (ϕ) as 397.7 kN/m2, 99.49 kN/m2 and 20.60 respectively. The soil is impervious and very good embankment fill material to serve as dam core and embankment fill due to its impermeable nature. The values of the geotechnical properties are within the threshold for suitable as fill material. Therefore, the test samples were confirmed suitable for use as fill material for earth dam construction.