Structural Engineering and Mechanics

Volume 70, Number 6, 2019, pages 765-779

DOI: 10.12989/sem.2019.70.6.765

A full path assessment approach for vibration serviceability and vibration control of footbridges

Qiankun Zhu, Xiaoli Hui, Yongfeng Du and Qiong Zhang

Abstract

Most of the existing evaluation criteria of vibration serviceability rely on the peak acceleration of the structure rather than that of the people keeping their own body unmoved on the structure who is the real receiver of structural vibrations. In order to accurately assess the vibration serviceability, therefore, a full path assessment approach of vibration serviceability based on vibration source, path and receiver is not only tentatively proposed in this paper, taking the peak acceleration of receiver into account, but also introduce a probability procedure to provide more instructive information instead of a single value. In fact, semi-rigid supported on both sides of the structure is more consistent with the actual situation than simply supported or clamped due to the application of the prefabricated footbridge structures. So, the footbridge is regarded as a beam with semi-rigid supported on both sides in this paper. The differential quadrature-integral quadrature coupled method is not only to handle different type of boundary conditions, but also after being further modified via the introduction of an approximation procedure in this work, the time-varying system problem caused by human-structure interaction can be solved well. The analytical results of numerical simulations demonstrate that the modified differential quadrature-integral quadrature coupled method has higher reliability and accuracy compared with the mode superposition method. What\'s more, both of the two different passive control measures, the tuned mass damper and semi-rigid supported, have good performance for reducing vibrations. Most importantly, semi-rigid supported is easier to achieve the objective of reducing vibration compared with tuned mass damper in design stage of structure.

Key Words

footbridge; vibration serviceability; human-structure interaction; differential quadrature-integral quadrature coupled method; probability procedure; semi-rigid supported

Address

Qiankun Zhu, Xiaoli Hui, Yongfeng Du and Qiong Zhang: Institute of Earthquake protection and Disaster Mitigation, Lanzhou University of Technology, Lanzhou, Langongping Road 287, 730050, China Qiankun Zhu: Vibration Engineering Section, College of Engineering, Mathematics and Physical Science, University of Exeter, North Park Road, EX4 4QF Exeter, United Kingdom