Impact of secondary fault findings on the design of Izmit Bay Bridge in Turkey

ABSTRACT: Izmit Bay Bridge with a 1550 m main span will be the world’s 4th longest span suspension bridge when completed. The bridge crosses the Izmit Bay in western Turkey from North to South and situated at very close premises of North Anatolian Fault. Therefore, from the early stages of design, detailed geophysical and geotechnical surveys have been conducted to find out the faulting, and the consequent earthquake risk in the region to lay the required basis for detailed design. In this paper, the conceptual bridge design, the detailed geophysical studies and the implication of the faults revealed by those geophysical studies on the conceptual design are introduced.