A Simple Conceptual Model for Estimating the First Bending Natural Frequency of Bridge Superstructures

Abstract

Several parameters affect the bridge’s natural frequencies while parameters related to the geometric characteristics of bridge components are more important. Maximum span length (SL) (length of the main or longest span), deck width, number of girders and spans, and girder’s height can be regarded as the main influencing parameters. In this paper, the first bending natural frequency (FBNF) of bridge superstructures of typical structural systems is assessed analytically using a simple conceptual model considering the main analytical parameters. The results show that the FBNF of bridges is strongly related to the SL of the longest span. It means that the other parameters are considered indirectly and may not be essentially considered as influencing parameters.