Investigation of Some Engineering Characteristics of Soils in Burao Town, Somaliland

Soils are essential for supporting civil engineering structures like roads and buildings. Making a thorough investigation of underground conditions is crucial for successful and cost-effective substructure design, as inadequate geotechnical investigations can lead to poor designs, construction delays, costly modifications, environmental damage, remedial work, and potential structural failures with legal repercussions. This research assesses the engineering properties of soil in Burao town, focusing on vulnerable areas prone to weak soils due to water infiltration. Sampling from two locations near the Togdheer dry river involved excavation to 2.5 meters, yielding disturbed and undisturbed samples for laboratory testing. Findings indicated fine sand as the predominant soil type, with natural moisture contents of 12.77% and 17.25%, specific gravities of 2.50 and 2.63, and varying Atterberg limits. Grain size analysis revealed sand dominance (91.63% − 91.84%) and low silt and clay content. Compaction tests identified maximum dry densities ranging from 1.71 to 1.95 g/cm³ and optimum moisture content between 13.5% and 14%. Soil classifications indicate that it is well-graded sand (SW) according to the Unified Soil Classification System, making it suitable for drainage-oriented construction projects, even though it has a lower load-bearing capacity compared to clay or gravel soils. In this research, limitations observed included the absence of essential tests like California Bearing Ratio and triaxial shear strength at the Burao University laboratory; future research should include these tests for better soil behavior understanding. Additionally, a regulatory framework is needed in Somaliland to mandate geotechnical investigations for construction permitting, ensuring projects rely on accurate soil data to improve safety and integrity.