Dynamic performance of a suspended reinforced concrete footbridge under pedestrian movements

International Conference on Mechanical Engineering and Applied Composite Materials

机械制造;材料科学

Drygala, I.^1 ; Dulinska, J.^1 ; Kondrat, K.^1

Cracow University of Technology, Cracow, PL, Poland^1

关键词: Comfort conditions;    Dynamic forces;    Dynamic motions;    Dynamic performance;    Modeling of dynamics;    National roads;    Pedestrian movement;    Single users;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/307/1/012060/pdf
DOI  :  10.1088/1757-899X/307/1/012060

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

In the paper the dynamic analysis of a suspended reinforced concrete footbridge over a national road located in South Poland was carried out. Firstly, modes and values of natural frequencies of vibration of the structure were calculated. The results of the numerical modal investigation shown that the natural frequencies of the structure coincided with the frequency of human beings during motion steps (walking fast or running). Hence, to consider the comfort standards, the dynamic response of the footbridge to a runner dynamic motion should be calculated. Secondly, the dynamic response of the footbridge was calculated taking into consideration two models of dynamic forces produced by a single running pedestrian: a 'sine' and 'half-sine' model. It occurred that the values of accelerations and displacements obtained for the 'half-sine' model of dynamic forces were greater than those obtained for the 'sine' model up 20%. The 'sine' model is appropriate only for walking users of the walkways, because the nature of their motion has continues characteristic. In the case of running users of walkways this theory is unfitting, since the forces produced by a running pedestrian has a discontinuous nature. In this scenario of calculations, a 'half-sine' model seemed to be more effective. Finally, the comfort conditions for the footbridge were evaluated. The analysis proved that the vertical comfort criteria were not exceeded for a single user of footbridge running or walking fast.