Estimation formulas for natural frequencies of girder bridge and continuous rigid frame bridge

Abstract

This paper is concerned with the evaluation of natural frequencies for the design of simply supported girder bridges, continuous girder bridges, and continuous rigid frame bridges. There are two significant parameters affecting the vibration frequencies. The first parameter is called the span ratio γ while the second parameter is called the stiffness ratio κ. The approximate formulas in terms of these parameters are proposed for these three types of bridges. From the analysis results, it is found that the first mode shape of the continuous rigid frame bridge is mainly induced by the pier other than the superstructure, when the stiffness parameter κ is greater than 10. Finally, the method proposed herein may be adopted to investigate the natural frequency of other types of bridges.

Keywords:

• highway bridge
• continuous rigid frame bridge
• girder bridge
• dynamic characteristics
• natural frequencies
• estimation formulas

Acknowledgements

The authors are grateful to the valuable comments given by the reviewers and the detailed further polish of the English by Ali F. Naser and Mosbeh R. Kaloop.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the China Scholarship Council (the 2013 China State-Sponsored Postgraduate Study Abroad Programme), the National Natural Science Foundation of China [grant number 51308465], [grant number 50678051], [grant number 51108132], [grant number U1234208] and the Fundamental Research Funds for the Central Universities [grant number 2682014CX004EM]. The authors would like to express their deep gratitude to all the sponsors for the financial aid.