• Title/Summary/Keyword: vehicle-bridge vibration

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Assessment of ride safety based on the wind-traffic-pavement-bridge coupled vibration

  • Yin, Xinfeng;Liu, Yang;Chen, S.R.
    • Wind and Structures
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    • v.24 no.3
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    • pp.287-306
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    • 2017
  • In the present study, a new assessment simulation of ride safety based on a new wind-traffic-pavement-bridge coupled vibration system is developed considering stochastic characteristics of traffic flow and bridge surface. Compared to existing simulation models, the new assessment simulation focuses on introducing the more realistic three-dimensional vehicle model, stochastic characteristics of traffic, vehicle accident criteria, and bridge surface conditions. A three-dimensional vehicle model with 24 degrees-of-freedoms (DOFs) is presented. A cellular automaton (CA) model and the surface roughness are introduced. The bridge deck pavement is modeled as a boundless Euler-Bernoulli beam supported on the Kelvin model. The wind-traffic-pavement-bridge coupled equations are established by combining the equations of both the vehicles in traffic, pavement, and bridge using the displacement and interaction force relationship at the patch contact. The numerical simulation shows that the proposed method can simulate rationally useful assessment and prevention information for traffic, and define appropriate safe driving speed limits for vulnerable vehicles under normal traffic and bridge surface conditions.

The Effect of KTX Vehicle Size Adjustment on High-Speed Railway Bridge Vibration : Numerical Study (수치해석을 통한 KTX 객차 길이 조정이 고속철도교량의 동적거동 특성에 미치는 영향 연구)

  • Shin, Jeong-Ryol;Kim, Hyun-Min;Sohn, Hoon;Yun, Chung-Bang
    • Proceedings of the KSR Conference
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    • 2008.11b
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    • pp.854-863
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    • 2008
  • A high attention has been paid on the running safety of Korean high-speed train, KTX. In running of KTX on bridge, the running unsafety problem issued from a resonance phenomenon of bridge, which was usually caused by the periodic wheel-loads of train. Therefore, many researches on this running safety of train on bridge have been conducted by domestic or foreign researchers. In this paper, for PSC box-girder bridge which is the representative high-speed railway bridge type, some numerical analyses on the dynamic characteristics of bridge with the non-periodic wheel-loads through vehicle size adjustment were performed. These numerical analyses shows the fact that the resonance phenomenon on bridge was mitigated through vehicle size adjustment. Additional numerical analyses on the vibration reduction of bridge in accordance with the location of size-adjusted vehicle were performed. From these results, it was represented that the adjustment of vehicle size has an effect on the running safety of train as well as the ride comfort.

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Analysis of the Characteristics of Dynamic Frequency Responses in Railway Plate Girder Bridges (철도 판형교의 동적응답 주파수 특성에 대한 분석)

  • 오지택;최진유;김현민
    • Proceedings of the KSR Conference
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    • 2002.10b
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    • pp.1035-1040
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    • 2002
  • Railway plate girder bridges have characteristics that are not show dominant frequency in dynamic response frequencies like obtained vertical acceleration on the bridge during the train passing because the train loading relatively bigger than the bridge self-weight. This paper experimentally confirmed in FFT result has various frequencies due to inherent characteristic of railway train loading. To establish classification of dynamic frequency range in railway bridge acceleration during the train passing, vibration frequencies result from experimental test are analyzed concerning actuation vibration factors. Factors are train velocity, train type, mass ratio of vehicle/bridge, stiffness of bridge, bridge/track and vehicle/track. From the result, it is proposed that the frequencty classfication table with corresponding factors. Using the proposed table to develop rehabilitation technique of the plate girder bridge, to expect vibration reduction and comfort enhancement of the railway plate girder bridge.

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Dynamic interaction analysis of vehicle-bridge system using transfer matrix method

  • Xiang, Tianyu;Zhao, Renda
    • Structural Engineering and Mechanics
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    • v.20 no.1
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    • pp.111-121
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    • 2005
  • The dynamic interaction of vehicle-bridge is studied by using transfer matrix method in this paper. The vehicle model is simplified as a spring-damping-mass system. By adopting the idea of Newmark-${\beta}$ method, the partial differential equation of structure vibration is transformed into a differential equation irrelevant to time. Then, this differential equation is solved by transfer matrix method. The prospective application of this method in real engineering is finally demonstrated by several examples.

A new bridge-vehicle system part I: Formulation and validation

  • Chan, Tommy H.T.;Yu, Ling;Yung, T.H.;Chan, Jeffrey H.F.
    • Structural Engineering and Mechanics
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    • v.15 no.1
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    • pp.1-19
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    • 2003
  • This paper presents the formulation of a new bridge-vehicle system with validation using the field data. Both pitching and twisting modes of the vehicle are considered in the contribution of the dynamic effects in the bridge responses. A heavy vehicle was hired as a control vehicle with known axle weight, axle spacing and spring coefficients. The measured responses were generated from the control vehicle running at a particular speed at a test span at Ma Tau Wai Flyover. The measured responses were acquired using strain gauges installed beneath the girder beams of the test bridge. The simulated responses were generated using BRVEAN that is a self-developed program based on the proposed bridge-vehicle system. The validation shows that the bridge model is valid for representing the test bridge and the governing equations are valid for representing the motion of moving vehicles.

The Simulation and Experimental Study on the Bridge Response of AGT Bridge - Vehicle interaction System (AGT 시스템 교량-차량 상호작용에 의한 교량응답 시뮬레이션 및 실험)

  • Na, Sang-Ju;Kim, Ki-Bong;Song, Jae-Pil;Kim, Hyun-Ho
    • Proceedings of the KSR Conference
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    • 2007.11a
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    • pp.395-400
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    • 2007
  • LRT(Light Railway Train), which is a intermediate system of train and bus, is arose for the solution of subway construction cost and the transportation capacity of bus. LRT was introduced in 1980's. About 30 local governments are plan to introduce LRT or constructing LRT, at present. AGT(Automated Guide-way Transit) system, which is a kind of LRT, is operated without driver. Rubber wheeled AGT system can reduce the noise and vibration compare to steel wheeled AGT, so it is estimated as ideal transportation system for urban area. And live loads at bridge are classified as the static load of vehicle and the dynamic wheel contact load which is occurred from the interaction of bridge and vehicle vibration, and the surface roughness. In the case of AGT system, the dynamic increment factor of bridge is greater than the normal train bridge and roadway bridge, because, the weight of AGT vehicle is more light that the train of truck. The exact method for dynamic increment factor is experiment. But this method is needed much money and time, moreover, this method cannot be adopted in design. Therefore, a simulation program for the interaction of AGT bridge, vehicle and surface roughness was developed, in this study. And the program was verified by experiment. As a result, the accuracy of the simulation program can be verified.

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Dynamic analysis of metro vehicle traveling on a high-pier viaduct under crosswind in Chongqing

  • Zhang, Yunfei;Li, Jun;Chen, Zhaowei;Xu, Xiangyang
    • Wind and Structures
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    • v.29 no.5
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    • pp.299-312
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    • 2019
  • Due to the rugged terrain, metro lines in mountain city across numerous wide rivers and deep valleys, resulting in instability of high-pier bridge and insecurity of metro train under crosswind. Compared with the conditions of no-wind, crosswind triggers severer vibration of the dynamic system; compared with the short-pier viaduct, the high-pier viaduct has worse stability under crosswind. For these reasons, the running safety of the metro vehicle traveling on a high-pier viaduct under crosswind is analyzed to ensure the safe operation in metro lines in mountain cities. In this paper, a dynamic model of the metro vehicle-track-bridge system under crosswind is established, in which crosswind loads model considering the condition of wind zone are built. After that, the evaluation indices and the calculation parameters have been selected, moreover, the basic characteristics of the dynamic system with high-pier under crosswind are analyzed. On this basis, the response varies with vehicle speed and wind speed are calculated, then the corresponding safety zone is determined. The results indicate that, crosswind triggers drastic vibration to the metro vehicle and high-pier viaduct, which in turn causes running instability of the vehicle. The corresponding safety zone for metro vehicle traveling on the high-pier is proposed, and the metro traffic on the high-pier bridge under crosswind should not exceed the corresponding limited vehicle speed to ensure the running safety.

Constructing the mode shapes of a bridge from a passing vehicle: a theoretical study

  • Yang, Y.B.;Li, Y.C.;Chang, K.C.
    • Smart Structures and Systems
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    • v.13 no.5
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    • pp.797-819
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    • 2014
  • This paper presents a theoretical algorithm for constructing the mode shapes of a bridge from the dynamic responses of a test vehicle moving over the bridge. In comparison with those approaches that utilize a limited number of sensors deployed on the bridge, the present approach can offer much more spatial information, as well as higher resolution in mode shapes, since the test vehicle can receive the vibration characteristics of each point during its passage on the bridge. Basically only one or few sensors are required to be installed on the test vehicle. Factors that affect the accuracy of the present approach for constructing the bridge mode shapes are studied, including the vehicle speed, random traffic, and road surface roughness. Through numerical simulations, the present approach is verified to be feasible under the condition of constant and low vehicle speeds.

Traffic-induced vibrations at the wet joint during the widening of concrete bridges and non-interruption traffic control strategies

  • Junyong Zhou;Zunian Zhou;Liwen Zhang;Junping Zhang;Xuefei Shi
    • Computers and Concrete
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    • v.32 no.4
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    • pp.411-423
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    • 2023
  • The rapid development of road transport has increased the number of bridges that require widening. A critical issue in the construction of bridge widening is the influence of vibrations of the old bridge on the casting of wet joint concrete between the old and new bridges owing to the running traffic. Typically, the bridge is closed to traffic during the pouring of wet joint concrete, which negatively affects the existing transportation network. In this study, a newly developed microscopic traffic load modeling approach and the vehicle-bridge interaction theory are incorporated to develop a refined numerical framework for the analysis of random traffic-bridge coupled dynamics. This framework was used to investigate traffic-induced vibrations at the wet joint of a widened bridge. Based on an experimental study on the vibration resistance of wet joint concrete, traffic control strategies were proposed to ensure the construction performance of cast-in-site wet joint concrete under random traffic without interruption. The results show that the vibration displacement and frequency of the old bridge, estimated by the proposed framework, were comparable with those obtained from field measurements. Based on the target peak particle velocity and vibration amplitude of the wet joint concrete, it was found that traffic control measures, such as limiting vehicle gross weight and limiting traffic volume by closing an additional traffic lane, could ensure the construction performance of the wet joint concrete.

Experimental analysis of an asymmetric reinforced concrete bridge under vehicular loads

  • Thambiratnam, D.P.;Brameld, G.H.;Memory, T.J.
    • Structural Engineering and Mechanics
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    • v.9 no.1
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    • pp.17-35
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    • 2000
  • Dynamic response of a three span continuous bridge has been determined by full scale experiments on the bridge. In the experiments, a heavy vehicle was driven across the bridge at different speeds and along different lanes of travel and the strains were recorded at different locations. The bridge was made of reinforced concrete and was asymmetric in plan and in elevation. Frequencies and modes of vibration excited by the vehicle were determined. The dependence of the dynamic amplification on bridge location and vehicle speed was investigated and dynamic amplifications up to 1.5 were recorded, which was higher than values predicted by bridge design codes. It was evident that when this asymmetric bridge was loaded by an asymmetric forcing function, higher modes, which are lateral and/or torsional in nature, were excited. Dynamic modulus of elasticity and the support stiffness influenced the natural frequencies of the bridge, which in turn influenced the dynamic amplifications. Larger than anticipated dynamic amplification factors and the excitation of lateral and/or torsional modes should be of interest and concern to bridge engineers.