Fatigue Test on Integral Joint of the Main Truss of the Baling River Bridge

2009 ◽  
Vol 417-418 ◽  
pp. 481-484 ◽  
Author(s):  
Gao Liu ◽  
Wen Ming Wu ◽  
Liang Tang ◽  
Tian Liang Wang
Keyword(s):  
Fatigue Test ◽  
Fatigue Resistance ◽  
Suspension Bridge ◽  
Scale Model ◽  
Fatigue Reliability ◽  
Truss Bridges ◽  
Long Span ◽  
Load Spectra ◽  
Main Girder ◽  
Test Result

The Baling River Bridge is a single-span simply-supported suspension bridge with a main span of 1088 m. The steel stiffening truss is employed as its main girder and comprises the integral joints connecting the chord members. The integral joint is a key structure and determines the safety of the bridge, but it is very complex in detail and has an undefined fatigue resistance. In order to investigate its mechanical behavior and fatigue reliability, a fatigue test was performed on a 1:1.4 scale model of the integral joint of the main truss of the Bridge. With an assumption of the load spectra represented by the standard fatigue vehicle in BS 5400, the test fatigue load was derived accounting for the multiple vehicle effect and the model scale. The test result shows that no cracks were detected in the model when subjected to two million stress range cycles, and the structure has an reliable fatigue resistance satisfying the design requirement. This type of integral joint is an alternative for long-span truss bridges.

Probabilistic Fatigue Damage Analysis of Long Span Suspension Bridge Due to Wind Induced Buffeting

2020 ◽  
Vol 980 ◽  
pp. 275-281
Author(s):  
Hu Jun
Keyword(s):  
Fatigue Life ◽  
Fatigue Damage ◽  
Time History ◽  
Suspension Bridge ◽  
Wind Load ◽  
Strong Wind ◽  
Fatigue Reliability ◽  
Long Span ◽  
Fatigue Damage Analysis ◽  
Fluctuating Wind

In order to consider the fluctuating wind load induced fatigue problem of long span suspension bridge, fatigue reliability formula is modified by assuming the fatigue life is accord with the weibull distribution. Based on the accurate bridge buffeting analysis of time history, the stress time history of components of a suspension bridge in east sea China is simulated, and then the fatigue damages and reliabilities are calculated. The results indicate that the main cables and hangers have enough fatigue reliability under the fluctuating wind load, the fatigue failure will not occur; the stiffening girder has larger fatigue damage, under 40 / (m.s-1) mean wind speed action, the girder of mid-support section’s average fatigue life is only 3.103 years, so the girder’s damage under strong wind action should be taken seriously.

Impact Analysis of Tower Number on Automotive Live Load Effect in Suspension Bridge

2014 ◽  
Vol 1020 ◽  
pp. 124-129
Author(s):  
Zhi Gang Qi ◽  
Jun Dong ◽  
Bo Qiang Yao
Keyword(s):  
Mechanical Properties ◽  
Impact Analysis ◽  
Suspension Bridge ◽  
Suspension Bridges ◽  
Load Effect ◽  
Bridge Programs ◽  
Long Span ◽  
The Difference ◽  
Main Girder ◽  
Bridge Models

As a bridge with a large span, suspension bridge has obvious advantage in the current cross-sea engineering. In order to achieve longer span capacity, long-span multi-tower suspension bridge programs were repeatedly proposed. Due to the increase in the number of tower, the mechanical behavior would be inevitably different with the ordinary two-tower suspension bridge. For better grasp the difference of the mechanical properties, Midas civil 2011 is used to model to analyze. Suspension bridge models whose spans are 1080m with different towers (two, three, four, five, six,) are established to analyze the change in the mechanical properties under the action of vehicle load. The results show that the mechanical properties of multi-tower suspension bridge are quietly different from two-tower suspension bridge and with the increase in the number of bridge tower, the displacements of main girder and main tower have large difference. When the number of tower is more than or equal to four, multi-tower suspension bridges have little difference in the mechanical properties and that means multi-tower effect is not obvious.

scholarly journals Pseudo-Static Analysis on the Shifting-Girder Process of the Novel Rail-Cable-Shifting-Girder Technique for the Long Span Suspension Bridge

2019 ◽  
Vol 9 (23) ◽  
pp. 5158
Author(s):  
Quan Pan ◽  
Zhuangpeng Yi ◽  
Donghuang Yan ◽  
Hongsheng Xu
Keyword(s):  
Static Analysis ◽  
Suspension Bridge ◽  
Theoretical Method ◽  
Scale Model ◽  
The Novel ◽  
Mountain Areas ◽  
Long Span ◽  
Main Cable ◽  
Specific Distribution ◽  
Static Responses

The rail-cable-shifting-girder (RCSG) technique is a new erecting method for the main girders of the long span suspension bridge in rural mountain areas with poor transportation and no navigable rivers for carrying large components. The pseudo-static analysis of the shifting-girder process for this girder erecting technique is performed. The global mechanical model of the double-layer cable system in the shifting-girder process is established, by analytically modeling the main-cable, rail cable, and slings according to cable’s basic assumptions. Based on the flexible cable theory, the main-cable segments are simulated as segmental catenary elements, the slings are considered as straight cable elements, the rail-cable segment that the shifting-girder trolley is moving on is simulated as multiple straight cable elements and other rail-cable segments are considered as single straight cable elements. The solving program is developed to obtain the pseudo-static responses including the forces and deflections of the shifting-girder system undergoing girder loads. Meanwhile, a global indoor reduced-scale model of shifting-girder system is designed to validate the presented theoretical results, by taking the Aizhai suspension bridge as engineering background. The results from the presented theoretical method match well with the measured experimental results of the indoor model test. The forces and deflections of the main-cable, rail-cable, and slings for the 21 working cases of erecting girder segments exhibit some specific distribution regularities. The presented theoretical method is able to correctly and effectively solve the pseudo-static responses of the RCSG system undergoing girder loads for the long span suspension bridge adopting the construction method of the RCSG technique.

Considering frictional slippage at saddle-cable interface in seismic behavior of a suspension bridge

2020 ◽  
pp. 136943322097477
Author(s):  
Canhui Zhao ◽  
Jiahong Duan ◽  
Xianzhi Zeng ◽  
Kailai Deng ◽  
Jia Guo ◽  
...  
Keyword(s):  
Seismic Energy ◽  
Suspension Bridge ◽  
Suspension Bridges ◽  
Deformation Pattern ◽  
Earthquake Excitation ◽  
Long Span ◽  
Dynamic Analyses ◽  
Nonlinear Dynamic Analyses ◽  
Main Girder ◽  
Nonlinear Numerical Model

Long-span suspension bridges are widely used in deep valleys, which face severe seismic risk. However, the potential saddle-cable frictional slippage under earthquake excitation as well as its influence on the seismic response of the whole suspension bridge has not yet been investigated. To investigate the effect of frictional slippage at the saddle-cable interface, this paper developed a nonlinear numerical model that considers the saddle-cable slippage. Another contrasting model with a non-slipping saddle-cable interface was used for quantitative comparison. Nonlinear dynamic analyses were conducted using these two models. The saddle-cable interfacial response indicated the realization of the frictional slippage at the saddle-cable interface under the maximum considered earthquake. The overall damage patterns, critical sectional performance, main girder drift, and energy dissipation were discussed in detail. Under the design based and maximum considered intensities, the saddle-cable slippage was seldom observed. The visible frictional slippage was encountered only at ultimate safety earthquake, which could be helpful to limit the transferred load, protect the pylon from yielding, and dissipate approximately 14% of the input seismic energy. While the slippage could not evidently affect the overall deformation pattern of the suspension bridge, as well as the response of bearings and central buckles.

Control of Vibrations due to Moving Loads on Suspension Bridges

2006 ◽  
Vol 11 (3) ◽  
pp. 293-318 ◽  
Author(s):  
M. Zribi ◽  
N. B. Almutairi ◽  
M. Abdel-Rohman
Keyword(s):  
Bridge Deck ◽  
Suspension Bridge ◽  
Lyapunov Theory ◽  
Dynamic Responses ◽  
Suspension Bridges ◽  
Control Force ◽  
Moving Loads ◽  
Hydraulic Actuator ◽  
Long Span ◽  
Suspended Cables

The flexibility and low damping of the long span suspended cables in suspension bridges makes them prone to vibrations due to wind and moving loads which affect the dynamic responses of the suspended cables and the bridge deck. This paper investigates the control of vibrations of a suspension bridge due to a vertical load moving on the bridge deck with a constant speed. A vertical cable between the bridge deck and the suspended cables is used to install a hydraulic actuator able to generate an active control force on the bridge deck. Two control schemes are proposed to generate the control force needed to reduce the vertical vibrations in the suspended cables and in the bridge deck. The proposed controllers, whose design is based on Lyapunov theory, guarantee the asymptotic stability of the system. The MATLAB software is used to simulate the performance of the controlled system. The simulation results indicate that the proposed controllers work well. In addition, the performance of the system with the proposed controllers is compared to the performance of the system controlled with a velocity feedback controller.

The Fatigue Reliability Evaluation & Improvement of the Single-Arm Subway Current Collector

2012 ◽  
Vol 215-216 ◽  
pp. 826-831 ◽  
Author(s):  
Yu Chen ◽  
Zhi Ming Liu ◽  
Qiang Li
Keyword(s):  
Fatigue Life ◽  
Calculation Result ◽  
Dynamic Stress ◽  
Current Collector ◽  
Reliability Evaluation ◽  
Fatigue Reliability ◽  
Railway Vehicles ◽  
Load Spectra ◽  
Reliability Method

This study developed a fatigue reliability method for evaluating and improving the key parts on railway vehicles, which was applied to real structures. The study involved a type of single-arm current collector, while its contact shoe often collapsed in operation and needs improvements. The dynamic stress data from the actual line was tested and converted to load spectra based on damage consistency rule, and then the fatigue life of the contact shoe structure was achieved. The calculation result comes to correspond to its operation life. Based on the method, an improving plan for the structure was developed under optimizing algorithms.

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