INVESTIGATION OF GEOTECHNICAL PROPERTIES OF SELECTED FAILED ROAD SOIL IN SOUTHWEST NIGERIA

ABSTRACT The study investigation of geotechnical properties of selected failed road soil in southwest Nigeria. The objective of the study evaluate the load-bearing capacity and compaction characteristics of the soil to determine its adequacy for supporting road infrastructure. study was carried out is strictly limited to a failed highway intersection at xxx Ado-Ekiti in Ekiti state, Nigeria. We visited the site to collect the representative samples (3) for the test by digging 2ft into one end of the pavement shoulder and each sample was taken 5 meters apart from the other. The test was performed using material left over from the thoroughly mixed portion of the soil prepared for the liquid limit test, which normally was at a moisture content higher than the plastic limit. The finding show the compaction test (West African Level) are displayed in Table 4.4.2. The maximum dry density of the soils ranged from 1420 kg/m³ to 2620 kg/m³, while the optimum moisture content varied between 8.4% and 34%. In conclusion, The geotechnical properties of soils from selected failed road sections in Southwest Nigeria has highlighted critical factors contributing to road deterioration in the region. The analysis revealed that the physical and mechanical properties of the soil, such as low load-bearing capacity, poor compaction characteristics, and insufficient shear strength, are significant contributors to the instability of these road sections. The study therefore recommend that, Implement Soil Stabilization Techniques: To improve load-bearing capacity and reduce plasticity in weak soils, stabilization methods such as lime, cement, or fly ash treatment should be applied.