• KSCE Journal of Civil and Environmental Engineering Research
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• v.14 no.1
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• pp.63-70
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• 1994

This study presents the nonlinear dynamic analysis method of the multi-span continuous bridge considering the friction of the expansion bearings. Also the numerical analysis is performed for estimating the effect of the friction on the seismic response of the multi-span continuous bridge under the longitudinal ground motion compatible to Korean bridge design response spectra. It is found that even small friction coefficient of the expansion bearings has significant effect on reducing the superstructure displacement due to energy dissipation and distributing the inertia force of the superstructure to the substructures due to frictional force. It is observed that such favorable friction effects increase as the friction coefficient increases and the magnitude of the ground motion decreases. Therefore, the friction of the expansion bearings can be effectively used for the safe and economic design of the continuous span bridge with many spans and large superstructure weight under the small to medium scale longitudinal ground motions.

• Journal of Korean Society of Steel Construction
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• v.18 no.4
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• pp.469-480
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• 2006

The goal of this study is to ases the static and dynamic behavior of disk bearings under railway vehicle loadings. Several static tests were conducted in a laboratory t bearings, all having the same kind of polyurethane disk as used in the static tests, were installed under a full-sized railway bridge and tested with a running locomotive, the tests results, the static and dynamic stiffness of the disk bearings were estimated and compared. the deformation of the disk bearings under the bridge was measured at varying disk bearing was almost half of that under dynamic loading. In addition, the dynamic stiffness of the fixed disk bearing was 80% higher than that of an expansion disk bearing, since the PTFE in the expansion bearing is displaced. The deformation of the disk bearing did not vary significantly with changes in locomotive's speed. The results of this study can contribute to fast-tracking the formulation of a design technique for disk bearings for railway bridges.

• Journal of the Korean Society for Railway
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• v.15 no.1
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• pp.62-70
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• 2012

Dynamic behaviors of line type bearings, spherical bearings and disk bearings which are being used for railway steel bridges are investigated, and that of the bridges is also analyzed. For the purpose, the vertical displacements of the three bearings including fixed and expansion type are measured and analyzed. Also, the deformation of the PTFE plate placed inside of spherical and disk bearings of expansion type is measured and its effect on the dynamic behavior of the bridges is discussed. The up-lift phenomenon at the bearings installed for the steel bridges is estimated. The vertical displacements at mid-span of the bridges are compared according to the bearing types. Finally, the 1st mode natural frequencies are estimated and the relationship to the vertical displacement is discussed.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1998.10a
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• pp.373-380
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• 1998

3D finite element analyses of movable bearing shoe and hinged bearing shoe are performed. The finite element models are built using MSC/PATRAN and analyses are carried out using MSC/NASTRAN. Results are again completely processed using MSC/PATRAN. From the results of the analyses, trends of deformation and stress distribution are reviewed and important factors to consider in the design of bearing shoes are discussed. Furthermore optimum crowning amount for the roller of movable bearing shoe was determined according to the results of the analyses.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.7
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• pp.51-57
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• 1999

Recently, long large bridges are built for mass transportation. Movable bearing shoes are important components of the bridges because they support movement of translation and rotation of bridge. In design stage of the long large bridges, detailed analyses using the finite element method are performed to guarantee safety and reliability. For that purpose, three-dimensional modeling is carried out by I-DEAS software and finite element analysis by ANSYS software. Results of the analyses are reviewed and important design factors for movable bearing shoes are discussed.

• Journal of the Korean Society for Railway
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• v.7 no.1
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• pp.51-56
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• 2004

경부고속철도 제7-2공구 현장은 충청북도 영동군 심천면 초강리에서 영동읍 화신리에 이르는 총연장 10km의(182k800∼199k800) 고속철도 노반공사 현장으로서 총 연장 중 교량공은 3.6km, NATM터널 2.6km, 그리고 토공 3.8km로 구성되어 있다. 이중 교량공은 PC Box 연속교(2@40m, 2@25m, 3@25m 등)가 주를 이루고 있으며 가설공법으로는 현장타설공법인 FSM(Full Staging Method) 공법을 채택하였다. 교량의 받침 형식으로는 고정단에는 포트받침 그리고 가동단에는 탄성받침이 적용되었다(참조 : www.ktx7-2.wo.to). (중략)

• Nuclear industry
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• v.7 no.4 s.50
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• pp.60-65
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• 1987

미국 NRC는 현재 가동중이거나 신규건설될 원전플랜트에 적용할 중대사고예방 및 축소에 관한 세부적인 정책안을 마련하여 시행중이다. 이를 위해서는 중대사고의 성격과 결과에 대한 철저한 연구에 의해 뒤받침 되는 규제 가이드라인의 제정이 필요하다.

• Journal of the Korean Society of Hazard Mitigation
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• v.1 no.1 s.1
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• pp.81-90
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• 2001

This paper presents the results of the parametric study on the longitudinal behavior of 2-span continuous railway bridge. To perform the main objective of this paper, the effects of pier shaft stiffness, pier height, the size of pier foundation, and the bearing stiffness on the longitudinal behavior of the bridges are studied. Within the limits of this study, the research result has revealed that the variation of the fixed pier is more effective than that of the moved pier. In addition, the control of the hearing stiffness is much less expensive than that of any other parameters.

• Journal of The Korean Society For Urban Railway
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• v.6 no.4
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• pp.383-392
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• 2018

This study investigated the change of additional axial stress of rail and reaction force at bridge bearings due to the track-bridge interaction when laying CWR on non-ballasted railway bridges including truss bridges with relatively long span. According to the results of the present study, additional axial stresses of rail and reaction forces at bridge bearings showed a large increase when CWR is installed on the non-ballasted railway bridge. The additional axial stress of rail can be acceptable if sufficient lateral resistance can be obtained. However, if the reaction force increases, there is a risk of damage of the bearing or pier, and therefore, it is necessary to take measures to mitigate the reaction force. It is found that additional axial stress of rail decreases when considering the frictional resistance of the bridge movable support, but its effect on the bearing reaction force is very small. On the other hand, when the longitudinal track restraint decreases, both additional axial stress of rail and bearing reaction force are reduced to a large extent. Also, when the ZLR fastening devices are applied to the region where the additional axial stress of rail is highest, bearing reaction force as well as additional axial stress of rail greatly decreased. Therefore, the application of ZLR fastening devices with the reduction of the longitudinal track restraints is very effective for installing CWR on non-ballasted railway bridges.