Investigation of a highway tunnel designed in weak rock masses by three dimensional numerical analyses (Evciler Variant Tunnel, Balıkesir, Turkey)

Turkey's geological and topographical structure, raises the need for road transport in the tunnel. In recent years, the tunnel alternative has been evaluated by avoiding high cuts on the highway routes. However, the most important point of tunnel construction is correct analysis and correct project planning. Correct analysis of the data obtained after the necessary field and laboratory studies helps to design an accurate project for any unit and geological structure that may be encountered during the manufacturing phase. The most frequently used analysis programs in tunnel project design only allow two-dimensional analysis. This is insufficient due to the effect of the tunnel and tunnel opening on the environment. The trouble-free completion of the tunnel construction depends on modeling the geological-geotechnical characteristics of the environment in which the tunnel will be opened in the most accurate way possible. This is achieved by three-dimensional modeling of the data obtained. In this study, three-dimensional numerical analysis of the Evciler Varyant tunnel designed in weak rock masses in Edremit district of Balıkesir province was performed. FLAC 3D software was used for numerical analysis. The excavation support system has been designed in accordance with the deformation values determined based on the analysis results.