SUBMITTED TO THE SCHOOL OF GRADUATE STUDIES OF ARBA MINCH INSTITUTE OF TECHNOLOGY IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE IN CIVIL ENGINEERING (GEOTECHNICAL ENGINEERING)

Abstract

Evaluating the stability analysis of embankment dam is an important, interesting, and challenging aspect of civil engineering. Dams are constructed for a various purpose including flood control, water sources, recreation, navigation, power generation, irrigation and so on. An embankment dam must be abel to sefly withstand static and dynamic loads that may be imposed upon it during its life time. This study was conducted to model stability analysis under steady state condition of embankment dams the cases of gidabo dam. Before conducting research, it was imperative to make a tough search for the data. This study mainly used two types of basic data, primary and secondary data. The analysis was carried out by finite element method via shear strength reduction technique using the finite element tool PLAXIS 8.2 and Geostudio software. Geostudio software occupied eight integrated applications equipped with special features to address several aspects of many geotechnical and geo-environmental engineering modeling of the interaction between the structures and the soil. Among these, sigma/w and seep/w to model by using finite element method. The output of sigma/w and seep/w are used as the input for slope/w package. Accordingly, the results of factor of safety on upstream and downstream slopes under steady state seepage full reservoir condition have been proven to be stable. As the result, upstream and downstream stability factor is 1.508 and 1.511 respectively. From the SEEP/W simulated result that the average flow rate of leakage for the entire length of the dam at the maximum water level of 1223.80 m a.s.l and minimum operating level of 1213m a.s.l was 3.84245e-8 m3/s and 1.1155e-8 m3/s respectively. All results of the settlement indicates that the impervious core material is safe against the inside cracking due to the horizontal displacement and the dam could not be affected by overtopping problem through the impact of current vertical settlements