Teferra, Alemayehu (Professor)Getachew, Anteneh2018-06-202023-11-112018-06-202023-11-112012-11http://etd.aau.edu.et/handle/12345678/1923Determination of the in situ engineering properties of foundation materials has always been a challenge for engineers practicing in developing countries. This usually leads to usage of unreliable designing methods. To avoid such problems, this research introduces the use of Dynamic Cone Penetration (DCP) which is a simple test device that is inexpensive, portable, and easy to operate and understand. In this thesis, field tests were conducted by locally manufactured dynamic cone penetration equipment from available materials. Laboratory tests needed to classify the soil and study the parameters that affect the dynamic cone penetration index were conducted. After analysing the data by categorising in to three categories, it has been found out that parameters like unconfined compression strength, liquidity index, depth, natural moisture content and bulk density have influence on the Dynamic Cone Penetration Index (DCPI). Undrained shear strength can be estimated by UCS=-197ln(DCPI)+735.5 with coefficient of determination (R2) of 71.1% for red clay soils of Addis Ababa and by UCS=895.8*DCPI-0.56 with R2 of 52.4%, for clayey soils including both red clay and black cotton soils of Addis Ababa combined. These good correlations were used to develop bearing capacity equation based on bearing capacity theory. The equation found were qult=-506.5ln(DCPI)+h+1891 for red clay soils of Addis Ababa and qult=2303.1*DCPI-0.56+h for clayey soils including both red clay and black cotton soils of Addis Ababa combined. The results are expected to have wide application in the construction sector.enGeotechnical EngineeringThesis