ABSTRACT
The proximity of the proposed Bosphorus tunnel site to the fault system in the Sea of Marmara (see Figure 1) as well as the critical site soil conditions makes the safe seismic design of the tunnel one of the most critical elements of the project. Current seismic design methodology for mass transit rail facilities has in general adopted a performance-based two-level design earthquake approach – a low level, high probability Functional Evaluation Earthquake (FEE) and a high level, low probability Safety Evaluation Earthquake (SEE). However, because of the unique seismological settings in the project region, the generally adopted two-level design earthquake approach is modified for this project.
