scholarly journals Traveling Wave Resonance and Simplified Analysis Method for Long-Span Symmetrical Cable-Stayed Bridges under Seismic Traveling Wave Excitation

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Zhong-ye Tian ◽  
Meng-lin Lou
Keyword(s):  
Wave Velocity ◽  
Traveling Wave ◽  
Longitudinal Direction ◽  
Wave Excitation ◽  
Seismic Responses ◽  
Excitation Process ◽  
Long Span Bridges ◽  
Traveling Wave Effect ◽  
Long Span ◽  
Wave Resonance

The seismic responses of a long-span cable-stayed bridge under uniform excitation and traveling wave excitation in the longitudinal direction are, respectively, computed. The numerical results show that the bridge’s peak seismic responses vary significantly as the apparent wave velocity decreases. Therefore, the traveling wave effect must be considered in the seismic design of long-span bridges. The bridge’s peak seismic responses do not vary monotonously with the apparent wave velocity due to the traveling wave resonance. A new traveling wave excitation method that can simplify the multisupport excitation process into a two-support excitation process is developed.

Nonlinear Seismic Response Analysis of Cable-Stayed Bridge under Uniform and Traveling-Wave Excitations

2015 ◽  
Vol 744-746 ◽  
pp. 793-798
Author(s):  
Kai Yan Xu
Keyword(s):  
Traveling Wave ◽  
Response Analysis ◽  
Wave Excitation ◽  
The Finite Element Method ◽  
Seismic Response Analysis ◽  
Nonlinear Seismic Response ◽  
Cable Stayed Bridge ◽  
Long Span ◽  
Flexible Component ◽  
Method Model

The finite element method model of a 670.56m span cable-stayed bridge was established and the dynamic characteristic and nonlinear earthquake-responses of it under uniform and traveling-wave excitations were systematic studied. Results show that: 1) its former 10 rank frequency are located very dense which shows that more modes shape should be considered when dealing with the dynamic analysis. 2) The traveling-wave excitation has greater effect on long-span cable-stayed bridge, especially on the more flexible component and great attention should be paid to the design of such kind of bridge.

scholarly journals Seismic Analysis of Hybrid System Bridge of Multi-Span Continuous Girder and Arches

2020 ◽  
Vol 165 ◽  
pp. 04032
Author(s):  
Kuihua Mei ◽  
Wangwang Fu ◽  
Jufeng Su
Keyword(s):  
Finite Element ◽  
Seismic Response ◽  
Wave Velocity ◽  
Traveling Wave ◽  
Seismic Isolation ◽  
Bending Moment ◽  
Internal Force ◽  
Wave Effect ◽  
Traveling Wave Effect ◽  
Large Mass Method

The Chengdong Hanjiang Bridge in Ankang City is a multi-span continuous beam-arch combination system bridge of (75+2×125+160+2×125+75) m, and its site is located in the earthquake zone. Calculation model based on Midas / Civil finite element software process analysis method is applied to seismic response analysis using power. At the same time, in order to influence the travelling wave effect and the seismic isolation system on the internal force of the bridge structure, corresponding finite element models were established and calculated with time history analysis. The finite element model under non-uniform excitation uses the “Large Mass Method” (LMM) for analysis and calculation under different wave velocity multi-point excitations. The results show that after considering the traveling wave effect, the displacement and bending moment of the control section of each hole increase, and the internal force of the fixed pier increases. When the wave velocity is 600m/s, the traveling wave effect strengthens the seismic response of the structure the most. With the increase of the wave velocity, the seismic response of the structure gradually approaches the seismic response under uniform excitation. After the friction pendulum seismic isolation support is used, it is fixed. The bending moment of Pier No.32 has been reduced by 80%, the stiffness of the whole bridge is more balanced, the forces of each pier are relatively close, and the isolation effect is good.

Damper Optimization for Long-Span Suspension Bridges

2013 ◽  
pp. 112-125
Author(s):  
Hao Wang ◽  
Aiqun Li ◽  
Zhouhong Zong ◽  
Teng Tong ◽  
Rui Zhou
Keyword(s):  
Seismic Response ◽  
Optimization Method ◽  
Sensitivity Analyses ◽  
Suspension Bridges ◽  
Seismic Responses ◽  
Control Effect ◽  
Analytic Hierarchy ◽  
First Order ◽  
Traveling Wave Effect ◽  
Long Span

Long-span suspension bridges are becoming prevalent globally with the rapid progress in design methodologies and construction technologies. Although with apparent progress, the balance between excessive displacement and inner forces, under dynamic loads, is still a main concern because of increased flexibility and low structural damping. Therefore, effective controllers should be employed to control the seismic responses to ensure their normal operation. In this chapter, the combination of the analytic hierarchy process (AHP) and first-order optimization method are formulated to optimize seismic response control effect of the Runyang suspension bridge (RSB) under earthquakes, considering traveling wave effect. The compositive optimal parameters of dampers are achieved on the basis of 3-dimensional nonlinear seismic response analyses for the RSB and parameters sensitivity analyses. Results show that the dampers with rational parameters can reduce the seismic responses of the bridge significantly, and the application of the AHP and first-order optimization method can lead to accurate optimization effects.

Research on Longitudinal Seismic Response of Continuous Welded Rail on Bridge with High-Pier and Long-Span

2013 ◽  
Vol 838-841 ◽  
pp. 1063-1068
Author(s):  
Jie Ling Xiao ◽  
Xian Kui Wei ◽  
Ping Wang ◽  
Meng Nan Zhang
Keyword(s):  
Traveling Wave ◽  
Seismic Waves ◽  
Longitudinal Force ◽  
Seismic Action ◽  
Apparent Velocity ◽  
Wave Effect ◽  
Traveling Wave Effect ◽  
Long Span ◽  
High Pier ◽  
Earthquake Zone

Longitudinal seismic responses of CWR on bridges with high-piers and long-spans under uniform excitation and traveling wave effect were studied. Results are shown as follows: Under seismic action, rail longitudinal forces near beam joints increase greatly than rail expansion forces (due to beam expansion); Designing CWR on bridges with high-piers and long-spans needs to consider influences of traveling wave effect and wave spreading derection; With the increase of the apparent velocity of seismic waves, rail longitudinal force tends to decrease; We suggest that designing of CWR on bridges crossing high-intensity earthquake zone should consider impact of seismic action, and establish a reasonable check method.

Seismic Response of Long Span Continuous Rigid-Framed Steel Arch Bridge

2018 ◽  
Vol 763 ◽  
pp. 1087-1094
Author(s):  
Ai Rong Liu ◽  
Yong Lin Pi
Keyword(s):  
Seismic Response ◽  
Shear Wave ◽  
Traveling Wave ◽  
Wave Speed ◽  
Wave Effect ◽  
Earthquake Excitation ◽  
Arch Bridge ◽  
Shear Wave Speed ◽  
Traveling Wave Effect ◽  
Long Span

This paper investigates seismic responses of Xinguang Bridge, a 3-span continuous rigid-frame and steel-truss arch bridge. Earthquake excitation input is a key issue for the seismic analysis. This paper uses a finite element method to study the traveling wave effect on Xinguang Bridge and its interaction with the dynamic properties of the bridge under the condition of two steps and two levels probability. The seismic response of the bridge under the coincident earthquake excitation is also analyzed. Comparisons show that the seismic response of the long-span bridge by considering the traveling wave effect is much different from that under consistent earthquake excitation. The influence of the shear wave speed on the seismic response of the long span continuous bridge is also explored and the shear wave speed is found to greatly affect the wave shape and magnitude of the time-history of the longitudinal displacement at the crown of the main arch of the bridge. It is concluded that traveling wave effect and shear wave speed of ground have significant influences on the seismic response of the long span continuous rigid-framed and steel-truss arch bridge.

Empirical Mode Decomposition Application for Structural Seismic Responses

2012 ◽  
Vol 256-259 ◽  
pp. 2096-2101 ◽  
Author(s):  
Ri Dong Du ◽  
Yong Bo Yuan ◽  
Miao Chen
Keyword(s):  
Empirical Mode Decomposition ◽  
Large Mass ◽  
Displacement Curve ◽  
Seismic Responses ◽  
Long Span Bridges ◽  
Long Span ◽  
Long Span Bridge ◽  
Mode Decomposition ◽  
Geological Conditions ◽  
Large Mass Method

Large mass method is used to calculate structural seismic responses of long-span bridges. Due to the inherent characteristics of large mass method, the larger scale of long span bridge, different geological conditions, seismic input time delay of different foot stall, the displacement curve of seismic responses will be drifted and distorted from the normal. In this paper, Empirical Mode Decomposition（EMD) based on the large mass method is proposed to remove pseudo component and drift displacement. Then displacement response curve is reconstructed using the remaining components, the drift and distortion of structural seismic responses is successfully removed by this method.

Analysis of Traveling Wave Effect on Half-Through CFST Arch Bridge by Large Mass Method

2013 ◽  
Vol 540 ◽  
pp. 21-28 ◽  
Author(s):  
Jun Ma ◽  
Yan Li
Keyword(s):  
Seismic Response ◽  
Traveling Wave ◽  
Large Mass ◽  
Wave Effect ◽  
Arch Bridge ◽  
Traveling Wave Effect ◽  
Long Span ◽  
Cfst Arch Bridge ◽  
Internal Forces ◽  
Large Mass Method

For long span arch bridges, the traveling wave effect is an important aspect on seismic response of structure which cannot ignore. The Big Mass Method was used to analyze the seismic response of a half-through CFST arch bridge under both uniform and non-uniform excitations. The results showed that the traveling wave effect caused by non-uniform excitation led to more obvious seismic response in both internal forces and displacements. The skewback section was most dangerous. The waveform of internal forces caused by non-uniform excitation was quite similar to that caused by uniform excitation, but the amplitude of the latter is bigger than the former. It can conclude that the traveling wave effect would cause the unsynchronized vibration to the structure elements which led to the lager responses.

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