Seismic Design Guidelines for Super-Long-Span Cable-Supported Bridges in Korea

Bridges with usual span lengths have been designed according to the Korea Bridge Code which allows large inelastic displacements. This code is, however, not applicable to cable-supported bridges. Recently new seismic design guidelines are being developed as one of the core tasks to develop super long-span cable-supported bridge technologies. New design earthquakes and seismic performance criteria are defined. The detailed performance requirements are assigned to each component of bridge. General cable-supported bridges have been designed seismically against an earthquake with a return period of 2400 years, but new guidelines adopt an earthquake with a return period of 4900 years as a design earthquake. The performance of a cable-stayed bridge designed in a conventional way has been investigated for the new design earthquake.