In this study, the deep excavation of Cincin Station located along the Bağcılar - Otogar metro line which is currently under construction in Istanbul is modeled numerically. The excavation (depth 32.5 m) of the station is carried out with a surrounding slurry trench diaphragm wall and top-down construction method. The six slabs of the station building and the foundation mat are used as support elements. Lateral soil displacements are measured with inclinometers placed in the wall and nearby soil layers. The results of numerical analysis using soil profile and geotechnical parameters obtained from conventional field and laboratory tests and measured lateral displacements are compared. Then using the same soil model, soil displacements expected to occur if some other alternative excavation support systems were used is investigated. As alternative support systems use of steel pipes as internal bracing and a piled wall with pre-stressed tie-backs are considered. The calculated soil displacements for different support systems are compared with each other and the measured values. The effects of certain design parameters such as the rigidity of internal bracing elements, the pile diameters and the pre-stressing level of tie-backs are investigated through numerical analysis
