Discussions on Calculation Methods and Unfavorable Distributions of Equivalent Along Wind Loading on Bridges

摘要

The wind loading on flexible structures can be expressed in terms of mean wind loads, equivalent background wind loads and inertial wind loads. The inertial wind load is commonly calculated by modal analysis based on the random vibration theory. There are two methods available for calculating equivalent background wind loading: the LRC method and the modal analysis method introduced by Davenport. The former results in a background wind load distribution depending on the external wind load and influence functions, whereas the latter gives a distribution following the inertial load distribution. Two methods for calculating equivalent wind loads, based on the LRC method and the modal analysis method respectively, are studied herein, comparisons and contrasts between them are also discussed. Appropriate combination approach for modal analysis method is suggested, and numerical examples are given to exhibit the differences and equivalence between these two methods.