Henok, Fikre (PhD)Abenezer, Shiferaw2020-11-252023-11-282020-11-252023-11-282020-11http://etd.aau.edu.et/handle/12345678/23530There is a growing need for the construction of underground structures beneath buildings because of the scarcity of available space in Addis Ababa either for parking or other purposes. Because of that there is a need for deep excavations during construction of the structures, which shall minimize the ground movement caused by the structures to remain within the allowable limits. It’s the geotechnical engineer’s responsibility to properly study the soil-structure interaction and soil behavior to design a support structure which satisfies this requirement in addition to providing a safe working space. There are many ways to support deep excavations; among which diaphragm walls and contiguous piles are the most popular ones in Addis Ababa. There is a need to study the effect of different parameters prior to the construction for a safer design. Previous studies on anchored diaphragm walls show that the effect of excavation depth, depth of embedment, soil type, strut spacing, and stiffness of the anchored diaphragm wall but no consideration is given for the geometric properties of the ground anchor used. Therefore, this research presents a study of anchored diaphragm walls using Plaxis 2D for deep foundation support in dry excavation by performing parametric study on the anchor orientation, anchor length and the grout (geo-grid) length to compare their influence on the stability of the diaphragm wall. Available literatures on diaphragm wall had been carefully studied followed by a numerical analysis using Plaxis 2D on the representative base models. The comparison of the effect of the parameters are carried out by analyzing the result of the maximum horizontal displacement, vertical displacement, and bending moments induced in the diaphragm wall using FEM. The results of the parametric studies showed that increasing the anchor orientation more than 25ᴼ isn’t advisable unless the site situation inhibited the installation. It was found out that free anchor length beyond the assumed wage slip surface should be a minimum of 1 meter for a safe anchorage. Beyond the assumed wage slip surface, for the same length of anchorage, it was found out that longer free anchor length and shorter grout result in a better anchorage than a short free anchor length with longer grout for both expansive and red silty clay soil.Plaxis 2DAnchored Diaphragm WallDeep ExcavationsThesis