Buffeting reliability of bridges with structural uncertainties

The dynamic reliability of a long-span bridge under wind turbulence is of great concern to engineering practice. In this paper, a practical framework is presented to evaluate the buffeting reliability of long-span bridges, in which the stochastic natures of both wind fluctuations and structural parameters are taken into consideration. A two-step strategy is adopted in the proposed method to consider the effects on the buffeting reliability of the stochastic wind loads and random structural properties. The approximative explicit expression for conditional buffeting reliability under given structural parameters is first obtained using the response surface method, in which only the stochastic effects due to wind loads are involved. Then, based on the total probability theorem, the total buffeting reliability is calculated in conjunction with the Monte-Carlo simulation techniques, in which, in addition to the stochastic wind loads, the uncertainties of structural parameters are taken into account. The buffeting reliability analysis of the Yamen Bridge, China, a long-span cable-stayed bridge with a main span of 338 m, is conducted to illustrate the feasibility and effectiveness of the present approach, and the effects of structural uncertainties on the buffeting reliability of the bridge are investigated.