195 / 2019-07-31 15:04:42

Copula-based Study on Joint Values of Wind and Temperature Actions for Long-span Bridges Utilizing Long-term Meteorological Data

Wind action,Temperature action,Joint distribution,Archimedean copula,Bivariate return period

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Wind and temperature actions shall be considered simultaneously in the design of long-span bridges, but they might not reach their extreme values specified in the design specifications at the same time usually. Replacing the univariate characteristic values of wind and temperature actions with the joint values of them might be a reasonable way to reduce the actions applied to the long-span bridges. In the present paper, a copula-based technique to determine the joint values of wind and temperature actions for long-span bridges utilizing long-term meteorological data was proposed, and the Changtai Yangtze River Bridge which will be the cable-stayed bridge with the longest main span in the world when it is finished was taken as an example. The Archimedean copulas were adopted to establish the joint distributions of wind speed and air temperature by coupling the marginal distributions of them. The bivariate return period analysis was employed to assess the occurrence probabilities of different combinations of wind and temperature actions. Based on the proposed principal of “the bivariate design return period is equal to the univariate design return period”, several types of the joint values of wind and temperature actions were recommended for bridge design. Contrastive analysis shows that, when one of the wind and temperature actions is specified to be the univariate characteristic value, the other one might be no more than 60% of the univariate characteristic value in most cases.