Cekmekoy-Sancaktepe Metro Tunnel in Istanbul
In this study, field observations on cutter wear and breakages in between 2 stations (Carsi and Umraniye) of Uskudar-Umraniye-Cekmekoy-Sancaktepe Metro Tunnel in Istanbul are mentioned in relation to TBM operational conditions (such as instantaneous penetration rate, thrust, torque, etc.) and geological conditions (such as RQD, strength, Cerchar abrasivity), within the context of the projects supported by ITU (Bapso Project) and Tubitak (112M859). The metro line of 20 km having two tubes is recently commissioned to Dogus Construction Company by Istanbul Metropolitan Municipality. The geology in the study area includes siltstone-claystone, sometimes sandstone, and diabase dyke having 50 m of length. Two EPB TBMs with diameters of 6.57 m are used for the tunnel excavations.