Tadesse, Samuel (PhD)Tesfaye, Bezza2018-06-212023-11-112018-06-212023-11-112015-02http://etd.aau.edu.et/handle/12345678/2417Investigation of the ground conditions is used for the economical design of the sub structural elements. It is also necessary to obtained sufficient information on type, characteristics and distributions of a soil and rock underlying sites of proposed structures for feasibility and economic studies for a proposed project. The objective of this thesis is to investigate the engineering properties of soil found in Ziway town. To achieve its objective disturbed and undisturbed samples from different parts of the town were collected and laboratory tests were done on the collected samples. Grain size analysis tests revealed that, starting from few centimeters below the ground level to the depth of investigation which is three meters, the soil in Ziway town is mostly silts and silty sand. In which for silt soils of ziway town has clay content ranging from 6.72 to 10.93%, silt fraction 51.45 to 73.03%, sand fraction 15.16 to 40.4%, and gravel content from 0.84 to 1.88% and for silty sand soils clay content ranging from 0.66 to 4.41%, silt fraction 17.15 to 42.18%, sand fraction 52.06 to 81.3%, and gravel content from 0.89 to 1.6% Within the depth of exploration, the specific gravity of the town ranges from 2.40 to 2.62. These values are low compared with Arora, 2003, this is because the soils are light weighted. From the consistency limit test results, liquid limit ranges from 27–37 %, plastic limit from none plastic to limit ranges from 23 – 29% and plastic index from ranges 0-8%. Compaction tests carried out on samples collected from the study area revealed that the maximum dry density (MDD) ranges from1.22 to 1.55 g/cm3 and the optimum moisture content ranges from 22.6 to 35.8 percent. Shear strengh parameters from the graph of shear stress vesrsus displacement and maximum shear stress vesrsus applied vertical load respectively gives cohesion(C) and angle of internal friction (Φ). From those results the cohesion ranges from 2.90 to 20.15kPa and the angle of internal friction ranges from 19.80-28.40.enGeotechnical EngineeringThesis