Assessment of Shallow Geotechnical Properties, Koya City- North of Iraq

Abstract

This study can provide and used as a reference and guidance to estimate site characterization of Koya city soils. Furthermore the results obtained from the assessment can be used as potential inputs for designing structures by the city planner, civil and geotechnical engineers. In order to create a geotechnical evaluation and develop a general description for the subsoil of the study area, 33 testing stations was randomly choose through the city, each station includes 3-5 testing points. All the disturbed and undisturbed samples were predicted from (1.5-2.5) m depth below the ground level. The tests included evaluation of the visual soil classification, index properties that are liquid and plastic limits, specific gravity, grain size analysis, compaction properties in term of dry unit weight and optimum moisture content, furthermore evaluation of the swelling potential of the soil in term of soil activity also predicted. The results indicated that 18% of the testing stations were fine grain soils and 82% were coarse grain soils. The soil classification and geotechnical testing showed that there are high variety in the types of soils and their corresponding properties. This high variety is based on the variety of the geological formation of the study area adding to that the losses in fines from some station and increase of then in anther stations depend on erosion of the fines, transmission of them with moved water, then these fines regimented on other stations represent the most effective reasons. Furthermore the analysis of results shows that the fine grain soils have low swelling tendency. Results from standard compaction test showed that the average optimum content for coarse grain soils was 12.4% while the average maximum dry density was 2.0 g/cm3.