Research on Fluid Viscous Damper Parameters of Cable-Stayed Bridge in Northwest China

Xiongjun He,Xiang Xiao,Yongchao Yang,Yulin Deng

doi:10.1155/2017/4532325

Abstract

To optimize the aseismic performance of nonlinear fluid viscous dampers (FVD) of cable-stayed bridge in the highly seismic zone, Xigu Yellow River Bridge in northwest China is taken as an example. Nonlinear time-history analysis method is used to research on the relation among the internal forces, displacements, and damping parameters of the 650 tonnage FVD. The method of getting the minimum of binary functions is used to obtain the optimal parameters of FVD. Also, the 1 : 1 full-scale FVD model is made and used in the constitutive relation test. Then the test result of the damping parameters can be got by normal equation method. The optimized method to obtain the damping parameters is further verified. The results indicate that seismic response in key positions of the cable-stayed bridge can be reduced by installing longitudinal nonlinear FVD between the towers and girders if choosing reasonable damping parameters C and ξ. The optimal damping parameters can be calculated accurately by the proposed method of optimizing damping parameters of nonlinear FVD, and the constitutive relation test verifies the correctness of the optimization analysis method. Conclusions concerned can be applied to the design of nonlinear FVD for cable-stayed bridges.

Highlights

For cable-stayed bridges, under longitudinal earthquake input, different tower-girder connection forms will have significant influence on the internal force response of main towers and its foundations, on the displacements of girder end, and on the relative displacements of the girder and the approach bridge [1, 2]
Based on the above analysis, the seismic response in the tower bottom, the tower foundation, and the girder can be reduced effectively by installing longitudinal nonlinear fluid viscous dampers (FVD) between the towers and girders when the velocity index ξ is in the range of 0.4∼0.5 and the damping coefficient C is about 10,000 kN×(s/m)ξ
The following conclusions can be reached: (1) The FVD are longitudinally installed between the towers and girders in cable-stayed bridge, whose damping parameters have great significance on the seismic response

Summary

Introduction

For cable-stayed bridges, under longitudinal earthquake input, different tower-girder connection forms will have significant influence on the internal force response of main towers and its foundations, on the displacements of girder end, and on the relative displacements of the girder and the approach bridge [1, 2]. The aseismic performances of the damper are mainly determined by the designed values of damping parameters C and ξ. Researches have shown that choosing the reasonable damping parameters of FVD can reduce the seismic response of key positions of cable-stayed bridges [5,6,7]. The method, based on the constitutive relation test upon the FVD model, which is used to get the optimal value of the damping parameters of nonlinear FVD [10, 11], turns out to be useful for the design of FVD in cable-stayed bridges. Seismic response in key positions of the cable-stayed bridge can be reduced by installing longitudinal nonlinear FVD if choosing reasonable damping parameters

Project Overview

Parameter Analysis of Nonlinear FVD

Model Making and Experiment

Figure 7

Findings

Conclusion