Probabilistic Evaluation of Seismic Isolation Effects for a California High-Speed Rail Prototype Bridge

摘要

Increasingly, seismic isolation (SI) has been adopted in buildings and highway bridges to mitigate damage from earthquakes. However, its appropriateness in high-speed rail (HSR) bridges remains a topic of major concern for engineers and stakeholders. The effects of SI on the response of HSR bridge systems during future earthquakes need to be evaluated probabilistically accounting explicitly for all uncertainties associated with the seismic loading. To this end, this paper compares the probabilistic seismic responses of a California high-speed rail (CHSR) prototype bridge with and without seismic isolation. The uncertainties in the seismic responses for the isolated bridge and nonisolated bridge are quantified and compared to explore the effects of SI when accounting for the uncertainty of the seismic input. The probabilistic seismic response is evaluated using two alternative approaches, and the less restrictive-but computationally more expensive-approach is selected to quantify the beneficial and detrimental effects of SI for the CHSR prototype bridge. The pros and cons of SI identified in probabilistic terms require a trade-off design in applying SI to HSR bridges.