• Proceedings of the KSR Conference
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• 2004.10a
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• pp.1021-1027
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• 2004

This research analyzed dynamic responses of the preflex railroad bridge. Vertical deflection and acceleration induced by operating train loads and test train loads were measured. Deflection of bridge by train traveling satisfies deflection limitation regulation (L/800) about the concrete bridge, but compare with UIC standard, vibration acceleration happened fairly greatly. Also test result show that acceleration receives greatly effect about the speed than deflection. It must discuss about vibration acceleration problems for speed elevation hereafter.

• Journal of Korean Society of Steel Construction
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• v.18 no.1
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• pp.53-58
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• 2006

The aim of this paper is to verify the dynamics stability of the continuous PSC Box bridges on the high-speed Kyoung-bu railway when a high-sped train runs through it. An experimental study was carried out to investigate the dynamic behaviors of the PSC Box railway bridge, which had ben designed based on dynamic design criteria. As a result, it was determined that PSC Box railway bridges possess enough dynamics stability for use by high-speed trains. According to the result of a field test (dynamics measuring analysis) that was conducted, an application of the natural frequency of train speed and the adjustment of the bridge's span length will allow one to come up with a more economical and suitable bridge design. Furthermore, it was found that the continuous control of the bridge's dynamic behavior and the bridge's maintena nce require the recording of data. The results of this study are very important in evaluating the structural stability of high-speed line bridges.

• Journal of the Korean Society for Railway
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• v.1 no.1 s.1
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• pp.20-29
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• 1998

State of the art and current issues related with the RC and PSC structure system for the German magnetic levitation train "Transrapid" were investigated. The German magnetic levitation train adopted a new kind of a structure to enable high-speed transportation, which allows the use of the space over a ground. The loading from Transrapid is light-weight compared with a regular train due to load distribution to a supporting structure. Therefore, Transrapid is considered an economical and efficient transportation system, and is also an environmentally-sustainable structure. In this paper, the structural design and construction technology specific to a magnetic levitation train were discussed, and structural considerations related with an actual operation of the train were pointed out. In addition, the future research area of a magnetic levitation train was proposed.

• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.4
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• pp.125-135
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• 2015

The tendency of more longer span length being required economical in railway bridges is studying about PSC I shaped girder. In this case, it is important to analyze and choose the effective girder section for stiffness of bridge. This study investigates the dynamic properties and safety of PSC I shaped girder being used wide upper flange whose selection based on radii and efficiency factor of flexure for railway bridge in different span type. In addition, 40m PSC Box girder bridge adopted in Honam high speed railway is further analyzed to compare dynamic performance of PSC I shaped girder railway bridge with same span length. Time history response is acquired based on the mode superposition method. Static analysis is also analyzed using standard train load combined with the impact factor. Consequently, the result met limit values in every case including vertical displacement, acceleration and distort.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.480-493
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• 2007

Many railway-advanced countries are using the various types of track to reduce the track maintenance and repair cost according to the improvement of velocity. It spends on much maintenance and repair cost for ballast track due to abrasion of ballast, track irregularity and unisotropical ballast-support stiffness. The ballast track on railway bridge is accelerating the deterioration of ballast according to interaction of railway bridge and track. As continuing the deterioration, it is caused dynamic loads. Due to these effects, it increases negative loads of track and bridge. However, when designing the railway bridge, the effect of ballast track was applicate only dead load, so elastic behavior effect of ballast track is not influenced. Therefore, this paper presumes the stiffness of ballast track on railway bridge considering dynamic behavior of railway bridge, it was evaluated that effect on dynamic behaviors of railway bridge according to ballast track stiffness.

• Journal of the Korean Society for Railway
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• v.14 no.3
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• pp.222-227
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• 2011

The dropper supports the contact wire and is attached using various types of dropper clips on the catenary. Droppers are subject to mechanical stress from buckling during the passage of pantographs. In order to investigate failure causes for the high speed line dropper, theoretical analyses and experiments have been carried out. In this paper, mathematical formulas are derived for the pre-sag of the dropper static load. The measured values in the experiment were similar to the theoretical predictions. To analyze the cause on fracture of dropper wire, we have conducted analysis such as SEM(Scanning Electron Microscope) of fractured specimens in the field and new specimens. Finally, we performed measurement for the variation of dynamic load on the dropper when a pantograph moved at 300km/h under the Korean high speed overhead line. If such mechanical load occur repeatedly with every passing pantograph, it is possible that the dropper wire will break due to fatigue. This results will be used for special management of high speed catenary system maintenance and life estimation of dropper.

• Journal of Korean Society of Steel Construction
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• v.19 no.3
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• pp.281-290
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• 2007

In this paper, the dynamic behavior of a 12m plate girder railway bridge is analyzed using the commercial FEM program. A time history load is applied to a standard train load via the shape function ofthe beam element. In addition, lateral behavior characteristics were simulated using the Klingel sine movement. A feasibility study of the FEM program and an analysis were performed by comparing the displacement and the acceleration, from the experimental data and the results of the FEM analysis. the time history of the lateral and vertical displacements are reflected in the experimental results. Six kinds of reinforcements were studied from the effects of the displacement and the acceleration. The RF-1 model that was applied to the upper lateral bracing system, and the RF-3 model that reinforced the plate, turned out to be the most effective reinforcement methods with respect to weight limits and construction simplification.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.3
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• pp.75-82
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• 2019

Slab panels are very important to develop asphalt concrete (AC) track for minimizing the roadbed stress due to the train load and reducing the plastic deformation of infrared-sensitive AC. In this study, the slab panel for AC track was developed through the shape design and the indoor performance test and its structural integrity has been investigated through the finite element analysis under the flexural tensile stress and the design moment according to various static load combination by KRL-2012 standard train load model and KR-C code. In order to verify the suitability of the slab panel for AC track, static bending strength test and dynamic bending strength test were performed according to EN 13230-2. Results show that the slab panel for AC track satisfies all the performance standards required by European standards such as crack loads and crack extension.

• Journal of the Korean Society for Railway
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• v.16 no.4
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• pp.305-310
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• 2013

In general, it is difficult to measure dynamic responses of a bridge with stepwise increasing speed of a train during commercial service on a high speed railroad. However, before opening the 2nd stage of the Gyeongbu high speed railroad, there was an opportunity for field tests and measurements of the bridge with stepwise increasing speed(from 170km/ h to 315km/h). The measured responses were compared with the results of a developed bridge/train interaction analysis. Although good agreement was found throughout almost the entire range of speeds, relatively large differences were found in the vicinity of the critical speed at which resonance behavior of the bridge occurs. To investigate the cause of this, reanalyses are performed with re-estimated damping ratios from field tests.

• Journal of the Korean GEO-environmental Society
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• v.22 no.4
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• pp.5-13
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• 2021

The transition is the zone where support stiffness suddenly increases in the railway industry. If the support stiffness increases, differential settlement will occur at the transition due to difference of stiffness, and the differential settlement causes problems for the train running safety and the roadbed that supports the track. In particular, a study on differential settlement at bridge-earthwork transition was only conducted to considering railway load in most cases. However, these studies have not taken account of earthquake despite earthquake has been occurred frequently in the recent, and it is necessary to consider earthquake. Therefore, in this study numerical analysis has been performed by changing the inclination of approach block, which determines the shape of the transition, and earthwork in order to verify the effect of the shape of the transition on the dynamic behavior at the bridge-earthwork transition. The result shows that the dynamic behavior at the bridge-earthwork transition was affected by the shape of transition.