Geotechnical problems and solutions in underground rail system projects

In recent years, the geotechnical problems encountered in underground rail system projects constitute fundamental engineering challenges that directly affect the design, construction, and operation processes of these projects. The proper management of factors such as soil stability, groundwater control, and excavation safety is of critical importance for achieving schedule, cost, and safety objectives. In this context, soil improvement methods, risk management strategies, and multidisciplinary approaches play a decisive role in the success of projects. This thesis analyzes the impacts of soil conditions on the engineering design, the soil-related technical challenges encountered during the implementation process, and the engineering solutions developed, specifically within the context of an underground rail system project under construction in Istanbul. The soil behavior on-site is compared with the predicted design data, and the alternative engineering solutions developed during implementation are evaluated. This thesis is presented as a compilation study that systematically reveals a process reduced from general to specific, in which the factors affecting the project design and implementation processes are examined in detail on a station basis, within the framework of all station lines and work items of an underground rail system project. This study, which brings together field engineering experiences and theoretical analyses, proposes applicable and sustainable solutions for the effective management of soil-related uncertainties.