• Title/Summary/Keyword: 모형교량

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Dynamic Characterisics of the Bridge Retrofitted by Restrainer under Seismic Excitations Considering Pounding Effects (충돌효과를 고려한 Restrainer로 보강된 교량의 지진하중에 대한 거동특성분석)

  • 김상효;마호성;이상우
    • Journal of the Earthquake Engineering Society of Korea
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    • v.3 no.3
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    • pp.75-86
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    • 1999
  • An analysis model is developed to evaluate the dynamic responses of a bridge system under seismic excitations, in which pounding actions between girders are considered in addition to other phenomena such as nonlinear pier motion, rotational and translational motions of foundations. The model also considers the abutment and restrainers connecting adjacent girders to prevent the unseating failures. Using the developed model, the longitudinal dynamic behaviors of a bridge system are examined for various peak ground accelerations, and the effects of the applied restrainers are investigated. It is found that the restrainers reduce the relative displacement with the shorter clearance length as well as the higher stiffness of the restrainers for moderate excitations. However, in the region with strong excitations the restrainers may yield due to the large relative displacement. Therefore, the extension of support length in addition to restrainers may need to prevent the unseating failure more effectively.

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Dynamic Analysis of PSC Bridge for a High-Speed Railway Vehicle Using Improved 38-Degree of Freedom Model (개선된 38자유도 차량모델을 이용한 고속철 PSC교량의 동적거동해석)

  • Oh, Soon-Taek;Sim, Young-Woo;Lee, Dong-Jun
    • Journal of the Korea Concrete Institute
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    • v.22 no.6
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    • pp.797-803
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    • 2010
  • A dynamic analysis procedure is developed to provide a better estimation of the dynamic responses of pre-stressed concrete (PSC) box girder bridges on the Korea high speed railway. Particularly, a three dimensional numerical model including the structural interaction between high speed vehicles, bridges and railway endures to analyze accurately and evaluate with in-depth parametric studies for dynamic responses of bridge due to the high speed railway vehicles. Three dimensional frame element is used to model the PSC box girder bridges, simply supported span lengths 40 m. The high-speed railway vehicles (K-TGV) including a locomotive are used as 38-degree of freedom system. Three displacements (vertical, lateral, and longitudinal) as well as three rotational components (pitching, rolling, and yawing) are considered in the 38-degree of freedom model. The dynamic analysis by Runge-Kutta method which are able to analyze considering the dynamic impact factors are compared and contrasted. It is proposed as an empirical formula that the impact factors damaged the bridge load-carrying capacities occurs to the bride due to high-speed vehicle.

Dynamic Behavior Analysis of PSC Train Bridge Friction Bearings for Considering Next-generation High-speed Train (차세대 고속철의 증속을 고려한 PSC 철도교 마찰 교량받침의 동적 거동 해석)

  • Soon-Taek Oh;Seong-Tae Yi
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.27 no.6
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    • pp.39-46
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    • 2023
  • In this study, the dynamic behavior of friction bearings of PSC (Pre-Stressed Concrete) box train continuous bridge was numerically analyzed at 10 km/h intervals up to 600 km/h according to the increasing speed of the next-generation high-speed train. A frame model was generated targeting the 40-meter single-span and two-span continuous PSC box bridges in the Gyeongbu High-Speed Railway section. The interaction forces including the inertial mass vehicle model with 38 degrees of freedom and the irregularities of the bridge and track were considered. It was calculated the longitudinal displacement, cumulative sliding distance and displacement speed of the bridge bearings at each running speed so that compared with the dynamic behavior trend analysis of the bridge. In addition, long-term friction test standards were applied to evaluate the durability of friction plates.

Flow Characteristics and Riverbed Change Simulation on Bridge-intensive Section (교량밀집 구간의 흐름특성과 하상변동 모의)

  • Cho, Hong Je;Jeon, Woo Yeol
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.30 no.6B
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    • pp.589-598
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    • 2010
  • When the hydraulic structures, such as bridge and weir, are consecutively installed to a short section of a river with complicated cross section, analyzing the flow characteristics and the riverbed change modality of the river is very important. In the 250 m section of the Taehwa river near the Samho-bridge, which passes through Ulsan city, three bridges has been installed, and the tributary water is flowing into both up and downstream of the section. Due to these factors, when the flood occurs, the cross section of the river changes vastly by the water level change and scour. Even so, due to the fact that the Samho-bridge divides the section into two parts, the national river and the regional river, each part is being analyzed separately by the onedimensional model. In this study, the flow characteristics due to the bridge concentration and the tributary water inflow were jointly analyzed for both up and downstream by using the one-dimensional HEC-RAS model and the two-dimensional SMS model, such as RMA2. The riverbed change modality of the section was also investigated by using the SED2D model. The results showed that the water level difference between the HEC-RAS and RMA2 was 0.87 m when applied to the three consecutive bridges. The riverbed change simulation using SED2D showed that the maximum scour was 0.231 m and it occurred at the Samho-bridge, which located in the middle and has short pier distance. In conclusion, when planning the river maintenance for the regions with concentrated bridges or the sections with severe changes in cross-section and flow, estimating the flood elevation by two-dimensional model and establishing countermeasures for the scouring of the bridge are required. In addition, an integrated analysis on both the national river and the regional river is necessary.

The Dynamic Effect of Highspeed Trains on Railway Bridges (고속철도 차량의 주행이 교량에 미치는 충격효과)

  • Yu, Chul Soo;Kang, Young Jong;Kim, Jong Heun;Kweon, Jae Hyun
    • Journal of Korean Society of Steel Construction
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    • v.10 no.2 s.35
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    • pp.187-199
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    • 1998
  • The highspeed railway bridge which support continuous and high moving mass evalute the dynamic state and make the displacement of the bridge makes more or less, but up to this time the bridges are designed by the static design concept. for example when we design bridge we use impact factor, which only times the static load makes dynamic load. But becouse it simples. it can't express all of the effects. And so, in this report we study the modeling method of the moving mass and the dynamic factor.

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Experimental Evaluation for Damping Ratio Limit of Railway Bridge according to Structure Types (철도교량 구조형식별 감쇠비 하한값 산정을 위한 시험적 연구)

  • Min, Rak-Ki;Sung, Deok-Yong;Park, Yong-Gul
    • Journal of the Korean Society for Railway
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    • v.15 no.2
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    • pp.154-161
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    • 2012
  • The damping ratio of railway bridge has become one of the most important issues in dynamic design and dynamic stability of railway bridge. In the present study, laboratory and field test were performed for railway bridges such as a twin I-shaped steel composite girder, PSC box, steel box, PSC, IPC, PRECOM, preflex. The damping ratio of railway bridge according to structure types was estimated by logarithmic decrement method. Therefore, magnitude, frequency and amplitude of load did not affect damping ratio of railway bridge. Also, damping ratio limit of steel composite and PSC bridges was evaluated in 1.0%.

Full-Scale Test on Precast Concrete Arch Bridge with Reinforced Joint and Backfill (보강된 이음부와 뒤채움을 적용한 조립식 프리캐스트 콘크리트 아치교량의 실물모형실험)

  • Chung, Chulhun;Joo, Sanghoon;Choi, Dongchan;Lee, Jongyun
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.34 no.2
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    • pp.389-402
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    • 2014
  • In this paper, the load test of full-scale precast concrete arch bridges considering reinforced joint and backfill was conducted. It is an improved method that the reinforced joint enhanced the structural performance of conventional masonry arch system which was proposed by previous researchers. The models of full-scale test are $10m(span){\times}3m$ (rise) and $10m(span){\times}2m$ (rise), which are 2 meters in width. The critical load position was shown at a third-span from the results of the pre-analysis. Based on the this results, the positions of load, measuring items and points were determined in experiments. As a result, the maximum load capacity of the specimen $10m{\times}2m$, a relatively small rise to span ratio (compared to the specimen $10m{\times}3m$), was higher than the specimen $10m{\times}3m$. It was evaluated that all the specimens have sufficient structural performance on the design load.

Optimum Life-cycle Cost Design of Orthotropic Steel Deck Bridges (강상판교의 생애주기비용 최적설계)

  • Cho, Hyo Nam;Min, Dae Hong;Lee, Kwang Min
    • Journal of Korean Society of Steel Construction
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    • v.13 no.4
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    • pp.337-349
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    • 2001
  • This study present an optimum deck and girder system design for minimizing the life-cycle cost (LCC) of orthotropic steel deck bridges. The problem of optimum LCC design of orthotropic steel deck bridges is formulated as that of minimization of the expected total LCC that consists of initial cost, maintenance cost, expected retrofit costs for strength, deflection, and fatigue. To demonstrate the effect of LCC optimum design of orthotropic steel deck bridges, the proposed optimum LCC design is compared with the conventional method for orthotropic steel deck bridges design. From the numerical investigations, it may be positively stated that the proposed optimum design procedure for orthotropic steel deck bridges based on the LCC will lead to more rational, economical and safer design.

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