Typhoon-induced non-stationary buffeting response of long-span bridges in complex terrain

Abstract

This paper presents a framework for predicting typhoon-induced non-stationary buffeting response of long-span cable-supported bridges located in a complex terrain. First, a non-stationary typhoon wind model is proposed based on observations from measured typhoon wind data. The wind model includes mainly time-varying mean wind speed, mean wind speed profile and evolutionary power spectral density (EPSD) function. Typhoon-induced wind loading on a bridge deck is then represented by time-varying mean wind forces, non-stationary buffeting forces associated with time-dependent aerodynamic coefficients and self-excited forces characterized by time-dependent aerodynamic derivatives. A nonlinear static analysis is performed to determine time-varying mean wind response, whereas the pseudo excitation method is employed to compute the EPSD-expressed non-stationary buffeting response of a long-span cable-supported bridge. The proposed framework is finally applied to predict non-stationary buffeting responses of a long-span cable-stayed bridge located in a complex terrain during a strong typhoon as a case study. The case study demonstrates how to apply the proposed framework and the results show that the proposed framework is feasible and necessary.