• Title/Summary/Keyword: train-bridge system

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Aerodynamic performance of a novel wind barrier for train-bridge system

  • He, Xuhui;Shi, Kang;Wu, Teng;Zou, Yunfeng;Wang, Hanfeng;Qin, Hongxi
    • Wind and Structures
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    • v.23 no.3
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    • pp.171-189
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    • 2016
  • An adjustable, louver-type wind barrier was introduced in this study for improving the running safety and ride comfort of train on the bridge under the undesirable wind environment. The aerodynamic characteristics of both train and bridge due to this novel wind barrier was systematically investigated based on the wind tunnel tests. It is suggested that rotation angles of the adjustable blade of the louver-type wind barrier should be controlled within $90^{\circ}$ to achieve an effective solution in terms of the overall aerodynamic performance of the train. Compared to the traditional grid-type wind barrier, the louver-type wind barrier generally presents better aerodynamic performance. Specifically, the larger decrease of the lift force and overturn moment of the train and the smaller increase of the drag force and torsional moment of the bridge resulting from the louver-type wind barrier were highlighted. Finally, the computational fluid dynamics (CFD) technique was applied to explore the underlying mechanism of aerodynamic control using the proposed wind barrier.

Extracting Modal Parameters of Railway Bridge under the Action of High-speed Train Using TDD Technique (TDD기법을 이용한 고속철도 교량의 동특성 추출)

  • Kim, Byeong Hwa
    • Journal of Korean Society of Steel Construction
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    • v.20 no.6
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    • pp.761-771
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    • 2008
  • When the crossing frequency of a train meets the natural frequency of a railway bridge, the bridge is bound to become resonant. There are few available time response samples involving a train that passes a bridge at high speed. Very effective modal-parameter extraction techniques for such special high-speed railway bridge conditions are introduced in this paper. Utilizing the cross-correlations of the free-vibration responses after the train passes, mode shapes and the temporal modal parameters (e.g., natural frequency and damping ratio) are extracted using the TDD and SI techniques, respectively. This approach has been applied to a two-span steel composite bridge in the Kyung-Bu high-speed railway system. The estimation results were compared with those obtained using the existing methods. The results fully coincide with those that were extracted using the existing aforementioned technique.

Dynamic effect of high-speed trains on simple bridge structures

  • Adam, Christoph;Salcher, Patrick
    • Structural Engineering and Mechanics
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    • v.51 no.4
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    • pp.581-599
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    • 2014
  • In this paper the overall dynamic response of simple railway bridges subjected to high-speed trains is investigated numerically based on the mechanical models of simply supported single-span and continuous two-span Bernoulli-Euler beams. Each axle of the train, which is composed of rail cars and passenger cars, is considered as moving concentrated load. Distance, magnitude, and maximum speed of the moving loads are adjusted to real high-speed trains and to load models according to Eurocode 1. Non-dimensional characteristic parameters of the train-bridge interaction system are identified. These parameters permit a spectral representation of the dynamic peak response. Response spectra assist the practicing engineers in evaluating the expected dynamic peak response in the design process of railway bridges without performing time-consuming time history analyses.

Comparative study on displacement measurement sensors for high-speed railroad bridge

  • Cho, Soojin;Lee, Junhwa;Sim, Sung-Han
    • Smart Structures and Systems
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    • v.21 no.5
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    • pp.637-652
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    • 2018
  • This paper presents a comparative study of displacement measurement using four sensors that are being used in the field: they are a ring gauge, a laser Doppler vibrometer (LDV), a vision-based displacement measurement system (VDMS), and an optoelectronic displacement meter (ODM). The comparative study was carried out on a brand-new high-speed railroad bridge designed to produce displacements within a couple of millimeters under the loading of a high-speed train. The tests were carried out on a single-span steel plate girder bridge two times with different train loadings: KTX and HEMU. The measured displacement is compared as raw and further discussion was made on the measurement noise, peak displacement, and frequency response of four sensors. The comparisonsare summarized to show the pros and cons of the used sensors in measuring displacement at a typical high-speed railroad bridge.

In-situ test and dynamic response of a double-deck tied-arch bridge

  • Gou, Hongye;Zhou, Wen;Chen, Genda;Bao, Yi;Pu, Qianhui
    • Steel and Composite Structures
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    • v.27 no.2
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    • pp.161-175
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    • 2018
  • In this study, in-situ dynamic tests of the world's longest steel box tied-arch bridge over the Yangtze River, China, are reported. The double deck bridge supports highway and monorail systems at upper and lower levels, respectively. Strain, displacement, and acceleration responses were measured and used to investigate the vibration characteristics of the bridge when excited by running trains and/or trucks at a speed of 5-60 km/h, train braking, and truck bouncing. Impact factors were correlated with the running speed of trains and trucks. A three-dimensional finite element model of the coupled monorail-train-bridge vibration system accounting for track irregularities was established to understand the system behavior and validated by the experimental results. Truck bouncing was the dominant impact factor on bridge responses. The running speed of vehicles determined the riding comfort of traveling trains.

DEVELOPMENT OF THREE-DIMENSIONAL DYNAMIC ANALYSIS MODEL HIGH SPEED TRAIN-BRIDGE INTERACTION (철도 차량 - 교량 상호작용에 의한 3차원 동적 해석 모델 개발)

  • Dinh, Van Nguyen;Kim, Ki Du;Shim, Jae Soo;Choi, Eun Soo;Songsak, Suthasupradit
    • Journal of Korean Society of Steel Construction
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    • v.20 no.1
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    • pp.151-163
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    • 2008
  • A formulation of three-dimensional model of articulated train-b ridge dynamic interaction has been made for the Korean eXpress Train (KTX). Semi-periodic profiles of rail irregularities consisting of elevation, alignment, cross and gauge irregularities have also been proposed using FRA maximum tolerable rail deviations. The effects of rail joints and sleeper step were also included. The resulting system matrices of train and bridge are very spare, and thus, are stored in one-dimensional arrays, yielding a time-efficient solution. A numerical algorithm for computing bridge-train response including an iterative scheme is also formulated. A program simulating train-bridge interaction and solving this problem using the new algorithm is implemented as new modules for the f inite element analysis software named XFINAS. Computed results using the new program are then checked by that of the validated 2-D bridge-train interaction model. This new 3D analysis provides more detailed train responses such as swaying, bouncing, rolling, pitching and yawing accelerations, which are useful inevaluating passenger riding comfort. Train operation safety and derailment could also be directly investigated by relative wheel displacements computed from this program.

A Study on the Effects of a High-Speed Railway Bridge Vibration induced by Moving Train on the Adjacent Bridge (열차주행에 의한 고속철도 교량의 진동이 인접 교량에 미치는 영향에 관한 연구)

  • Kim Sung-Il;Lee Jang-Seok
    • Proceedings of the KSR Conference
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    • 2004.10a
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    • pp.900-905
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    • 2004
  • A study on the effects of a high-speed railway bridge vibration induced by moving train on the nearby bridge is performed. Longitudinal and lateral accelerations of slabs and piers which are calculated from moving load analysis of a high-speed railway bridge can be used as input ground motions for the adjacent bridge. Dynamic responses of the adjacent bridge considering soil-structure interaction effects are analyzed by sub-structure method. Analysis procedure is made of free field analysis, calculation of impedance and effective input load and soil-structure system analysis.

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Dynamic response of steel-concrete composite bridges loaded by high-speed train

  • Podworna, Monika
    • Structural Engineering and Mechanics
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    • v.62 no.2
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    • pp.179-196
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    • 2017
  • The paper focuses on dynamic analyses of a series of simply-supported symmetric composite steel-concrete bridges loaded by an ICE-3 train moving at high speeds up to 300 km/h. The series includes five bridges with span lengths ranging from 15 m to 27 m, with repeatable geometry of the superstructures. The objects, designed according to Polish standards valid from 1980s to 2010, are modelled on the bridges serviced on the Central Main Line in Poland since 1980s. The advanced, two-dimensional, physically nonlinear model of the bridge-track structure-high-speed train system takes into account unilateral nonlinear wheel-rail contact according to Hertz's theory and random vertical track irregularities equal for both rails. The analyses are focused on the influence of random track irregularities on dynamic response of composite steel-concrete bridges loaded by an ICE-3 train. It has been pointed out that certain restrictions on the train speed and on vertical track irregularities should be imposed.

A Dynamic Analysis of Rotations at the center of Vehicle Running High Speed KTX Train on the PSC Box Bridges (PSC 교량 위를 고속주행 중인 KTX 전동차의 중심회전각 동적해석)

  • Oh, Soon-Tack;Lee, Dong-Jun
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.18 no.1
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    • pp.59-67
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    • 2014
  • A dynamic analysis is carried out to provide an evaluation method of running safety for a PSC box bridge located on the Gyung-Bu high speed railway. The numerical models of bridge and train vehicle are developed in detail with corresponding interaction system. Three dimensional skeleton element model of PSC box bridge and 38-degree-of-freedom of vehicle are adopted from the existing properties of KTX bridge and train vehicle. Analysed three direction rotations of vehicle on the bridge and ground tracks are compared for running speeds up to 500 km/h with 10 km/h constant increments. The comparison of the rotations will be an improved evaluation method of Running Safety in stead of the existing standard method.

Evaluation of optimal ground motion intensity measures of high-speed railway train running safety on bridges during earthquakes

  • Liu, Xiang;Jiang, Lizhong;Xiang, Ping;Feng, Yulin;Lai, Zhipeng;Sun, Xiaoyun
    • Structural Engineering and Mechanics
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    • v.81 no.2
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    • pp.219-230
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    • 2022
  • Due to the large number of railway bridges along China's high-speed railway (HSR) lines, which cover a wide area with many lines crossing the seismic zone, the possibility of a HSR train running over a bridge when an earthquake occurs is relatively high. Since the safety performance of the train will be threatened, it is necessary to study the safety of trains running over HSR bridges during earthquakes. However, ground motion (GM) is highly random and selecting the appropriate ground-motion intensity measures (IMs) for train running safety analysis is not trivial. To deal this problem, a model of a coupled train-bridge system under seismic excitation was established and 104 GM samples were selected to evaluate the correlation between 16 different IMs and train running safety over HSR bridges during earthquakes. The results show that spectral velocity (SvT1) and displacement (SdT1) at the fundamental period of the structure have good correlation with train running safety for medium-and long-period HSR bridges, and velocity spectrum intensity (VSI) and Housner intensity (HI) have good correlation for a wide range of structural periods. Overall, VSI and HI are the optimal IMs for safety analysis of trains running over HSR bridges during earthquakes. Finally, based on VSI and HI, the IM thresholds of an HSR bridge at different speed were analyzed.