Simplified analysis of cable-stayed bridges with longitudinal viscous dampers

2020 ◽  
Vol 27 (8) ◽  
pp. 1993-2022
Author(s):  
Xu Li ◽  
Jun Li ◽  
Xiaoyi Zhang ◽  
Jianfeng Gao ◽  
Chao Zhang
Keyword(s):  
Shaking Table Test ◽  
Damping Ratio ◽  
Shaking Table ◽  
Great Success ◽  
Viscous Dampers ◽  
Content Type ◽  
Equivalent Damping ◽  
Long Span ◽  
Simplified Method ◽  
Cable Stayed Bridges

PurposeViscous dampers are commonly used in large span cable-stayed bridges to mitigate seismic effects and have achieved great success.Design/methodology/approachHowever, the nonlinear analysis on damper parameters is usually computational intensive and nonobjective. To address these issues, this paper proposes a simplified method to determine the viscous damper parameters for double-tower cable-stayed bridges. An empirical formula of the equivalent damping ratio of viscous dampers is established through decoupling nonclassical damping structures and linearization of nonlinear viscous dampers. Shaking table tests are conducted to verify the feasibility of the proposed method. Moreover, this simplified method has been proved in long-span cable-stayed bridges.FindingsThe feasibility of this method is verified by the simplified model shaking table test. This simplified method for determining the parameters of viscous dampers is verified in cable-stayed bridges with different spans.Originality/valueThis simplified method has been validated in cable-stayed bridges with various spans.

scholarly journals Experimental and Numerical Studies on Sloshing Dynamics of PCS Water Tank of Nuclear Island Building

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Xiaojun Li ◽  
Chenning Song ◽  
Guoliang Zhou ◽  
Chao Wei ◽  
Ming Lu
Keyword(s):  
Shaking Table Test ◽  
Cooling System ◽  
Damping Ratio ◽  
Time History ◽  
Hydrodynamic Pressure ◽  
Test Method ◽  
Shaking Table ◽  
Water Tank ◽  
Scaled Model ◽  
Sloshing Dynamics

Water tank is one important component of passive containment cooling system (PCS) of nuclear island building. The sloshing frequency of water is much less than structure frequency and large-amplitude sloshing occurs easily when subjected to seismic loadings. Therefore, the sloshing dynamics and fluid-structure interaction (FSI) effect of water tank should be considered when the dynamic response of nuclear island building is analyzed. A 1/16 scaled model was designed and the shaking table test was done, in which the hydrodynamic pressure time histories and attenuation data of wave height were recorded. Then the sloshing frequencies and 1st sloshing damping ratio were recognized. Moreover, modal analysis and time history analysis of numerical model were done by ADINA software. By comparing the sloshing frequencies and hydrodynamic pressures, it is proved that the test method is reasonable and the formulation of potential-based fluid elements (PBFE) can be used to simulate FSI effect of nuclear island building.

Seismic Displacements Reduction for a Long-Span Cable-Stayed Bridge

2011 ◽  
Vol 255-260 ◽  
pp. 840-845
Author(s):  
Xi Wen Yang ◽  
Zi Bao Lian
Keyword(s):  
Inertial Force ◽  
Center Of Gravity ◽  
Shear Forces ◽  
Viscous Dampers ◽  
Cable Stayed Bridge ◽  
Long Span ◽  
Seismic Shear ◽  
Seismic Displacements ◽  
Floating Systems ◽  
Cable Stayed Bridges

Floating or semi-floating systems are usually employed for long-span cable-stayed bridges to lengthen their fundamental periods, and accordingly, to reduce their seismic inertial force, but the structures’ seismic displacements could be increased by utilizing these systems. Taking Yong-jiang railway cable-stayed bridge which has a low center of gravity as engineering background, the function of viscous dampers in controlling seismic displacements is studied. Firstly, the rational parameters of dampers are determined by parametric analysis, and then the seismic displacements and forces of the bridge, utilizing and un-utilizing viscous dampers, are compared. The results show that: viscous dampers are efficient in controlling seismic displacements of the bridge; the seismic shear forces at the bottom of towers are reduced slightly and the corresponding moments are reduced in a larger extent for cable-stayed bridge with low center of gravity.

Investigation of the relationship between intensity measures and engineering demand parameters of cable-stayed bridges using intra-plate earthquakes

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Jin-Hai He ◽  
Yu-Tao Pang ◽  
Xinzhi Dang ◽  
Wan-Cheng Yuan
Keyword(s):  
Shaking Table Test ◽  
Element Model ◽  
Shaking Table ◽  
Fundamental Period ◽  
Intensity Measures ◽  
Content Type ◽  
Spectral Velocity ◽  
Nonlinear Finite Element Model ◽  
The Relationship ◽  
Engineering Demand Parameters

Purpose The purpose of the study is to investigate and reveal this relationship of various engineering demand parameters (EDPs) of this structural type and intensity measures (IMs) under intra-plate earthquakes. Design/methodology/approach The nonlinear finite element model used was calibrated first to the existing results of the shaking table test to verify the modeling technique. Findings This paper investigated the relationship between intensity measures and various engineering demand parameters of cable-stayed bridges using intra-plate earthquakes. The correlation analysis and Pearson coefficient are used to study the correlation between EDPs and IMs. The results showed that peak ground velocity (PGV)/peak ground acceleration, peak ground displacement and root-mean-square of displacement showed weak correlation with IMs. PGV, sustained maximum velocity, a peak value of spectral velocity, A95 parameter, Housner intensity and spectral acceleration at the fundamental period, the spectral velocity at the fundamental period and spectral displacement at the fundamental period were determined to be better predictors for various EDPs. Originality/value This paper investigated the correlation between the intensity measures of intra-plate earthquakes with the seismic responses of a typical long-span cable-stayed bridge in China. The nonlinear finite element model used was calibrated to the existing results of the shaking table test to verify the modeling technique. In total, 104 selected ground motions were applied to the calibrated model, and the responses of various components of the bridge were obtained. This study proposed PGV as the optimal IM.

Experimental and Simulation Study of a Hybrid Frame Structure with Viscous Dampers

2012 ◽  
Vol 446-449 ◽  
pp. 894-899
Author(s):  
Hong Mei Zhang ◽  
Xi Lin Lu ◽  
Chun Guang Meng
Keyword(s):  
Shaking Table Test ◽  
Time History ◽  
Shaking Table ◽  
Frame Structure ◽  
Nonlinear Time History Analysis ◽  
Seismic Action ◽  
Test Model ◽  
Viscous Dampers ◽  
Scaled Model ◽  
Nonlinear Simulation

A Concrete-filled Rectangular Steel Tube (CRST) frame structure is studied in this paper by shaking table model test and nonlinear simulation. A number of viscous dampers are employed to insure the function of the building especially under seismic action for some of the main vertical elements of the building are not continuous. A shaking table test of a scaled model was conducted under different earthquake waves to investigate the structural behavior. And the nonlinear time-history analysis for the shaking table test model was also carried out by finite element analysis program according to the shaking table test. The simulation model was constructed in accordance with the tested specimen and the simulation effect was then validated by the tested results. To sum up, (1) there are no obvious weak stories on the damping equipped structure; (2) the dampers can reduce the displacement of the irregular to a certain degree.

scholarly journals Shaking Table Test of High Pier and Small Radius Curved Bridge under Multi-point Excitation

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Lei Yan ◽  
Guo Li ◽  
Kang An ◽  
Kefeng Yue ◽  
Zhi Lin
Keyword(s):  
Seismic Response ◽  
Seismic Waves ◽  
Shaking Table Test ◽  
Damping Ratio ◽  
Shaking Table ◽  
Small Radius ◽  
Curved Bridge ◽  
Bridge Model ◽  
High Pier ◽  
The Impact

The non-uniform stratum and uneven surface have the complicated seismic spatial variability. The seismic response of high pier and small radius curved bridge caused by the seismic specificity of this kind of terrain has not been systematically studied. According to the multi-point excitation theory of long-span structures and the similar theory of shaking table test in model structures, a high pier with small radius curved girder bridge was used as the research object. The shaking table test of real bridge model was carried out to study the seismic response laws of this kind of bridge under multi-point excitation. The results show that the designed seismic wave expansion device can meet the test requirements. The frequency of the model structure decreases rapidly and the damping ratio increases during the whole test process. The local terrain effect amplifies the seismic response of high pier and small radius curved bridge. The seismic response of high pier and small radius curved bridge is affected by different frequency spectrum seismic waves, and there is a big difference. Based on the above results, the impact of multi-point excitation should be considered in seismic design of high pier with small radius curved bridge.

Shaking Table Test of a Long-Span Continuous Girder Bridge

2012 ◽  
Vol 446-449 ◽  
pp. 242-246
Author(s):  
Yan Jiang Chen ◽  
Da Xing Zhou ◽  
Wei Ming Yan ◽  
Zhen Yun Tang
Keyword(s):  
Shaking Table Test ◽  
Shaking Table ◽  
Long Span ◽  
Continuous Girder Bridge ◽  
Girder Bridge
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