Investigating the Effects of some Geotechnical Properties on Exploitation of some selected Laterite Deposits in South West, Nigeria

摘要

Investigation was carried out on the slope stability of lateritic soil due to effects of some geotechnical properties in selected burrow pits in Akure, Ibadan, Ewekoro and Iperu areas, south western, Nigeria. The geotechnical properties were determined in accordance with American Society for Testing and Materials (ASTM) Standards. The conventional slope stability analysis was based on the linear Mohr - Coulomb failure criterion utilizing the notion of safety factors with respect to shear strength, where their average results of cohesion, angle of friction, bulk density and moisture content from the locations are 82 kPa, 18 degree, 1700 kg/m~3, and 22% respectively. The average specific gravity for locations was 2.73. The degree of permeability was very low except for location 6 in Ibadan area which is medium. The grain size distribution for the locations was classified into SC - SM (silt clayey sand). From compaction test, average moisture content, average wet density and dry density for the locations are 23%, 1849 kg/m~3 and 1512 kg/m~3 respectively while the average compaction curve deduced 24% optimum moisture contents and 1639 kg/m~3 maximum dry density. The Atterberg limits test results indicate that locations 1 - 5 were recorded as plastic soil while location 6 non-plastic soil. Also, the linear shrinkage degree of expansion for location 1 - 5 indicates critical while location 6 indicates non-critical. Finally, statistical mathematical model equations were developed. The factor of safety for locations 1 - 5 was satisfactory for routine extraction and loading operations while location 6 was unsafe due to loading conditions of the terrain.