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Analysis on Visual Preference of Bridge Landscapes of View Point Selection and Bridge Shape for Improvement of the Rural Landscape - A Case Study of the 'Baegya Bridge of Yeosu City in Jeollanam-do' (농어촌경관 향상을 위한 교량경관의 조망점 및 형태에 관한 경관선호도 분석 -전라남도 여수시 백야대교를 대상으로-)

  • Chun, Hyun-Jin;Lee, June;Jiang, Long;Kim, Sung-Kyun
    • Journal of Korean Society of Rural Planning
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    • v.18 no.3
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    • pp.57-65
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    • 2012
  • This research is focus on the analysis of bridge image and preference. In this study, 3 types of bridge with arch bridge, cable stayed bridge, and suspension bridge, 4 prospect points named A, B, C, and D will be simulated in one scene for final analysis of bridge image and preference.On prospect point A, higher evaluation is received among the arch bridge. In addition, for cable stayed bridge and suspension bridge, the Higher evaluation is received among the most at the arch bridge on prospect point B. At the on prospect point C, higher evaluation is received among the most cable stayed bridge and suspension bridge compared with arch bridge. At the on prospect point D, lower evaluation is received among the cable stayed bridge and suspension bridge compared with arch bridge. The highest average total preference is received for cable stayed bridge. And, The lowest average total preference is received for arch bridge. Cable stayed bridge is suitable for the Baegya Bridge than arch bridge in the Landscape point. In conclusion, the preference for one bridge is not the same at different prospect points through above research.

Analysis on Visual Preference of Bridge Landscapes of Background and Shape in Rural Area - Focused on the Natural Landscape in Rural Area - (농촌지역의 교량의 배경경관 및 교량형태에 따른 시각적 선호도 분석 - 농촌지역 자연경관을 중심으로 -)

  • Chun, Hyun-jin;Jiang, Long;Cheng, Yu-ning
    • Journal of Korean Society of Rural Planning
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    • v.22 no.2
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    • pp.89-98
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    • 2016
  • Due to the rapid economic development of Korea, the bridge have been built by government over the several years. Additionally, there are too many mountain and river and the bridge have been built in rural area. But bridge designers weren't considering the bridge landscape. And bridge was a negative factor in regional landscape. Because of this, this study surveyed the landscape preferences of rural bridge landscapes according to different bridge types. The results were summarized as follows: And this research include conducting a study on visual preference according to the bridge's type and background. And, the landscape of arch bridge in the river 1 is landscape of the highest preference. The the landscape of girder bridge in the river 2 is landscape of the lowest preference. In the river 1 and 2 landscape, high preference is observed in the arch bridge and low preference is noted in the girder bridge. In the mountain 1 and 2 landscape, high preference is observed in the cable-stayed bridge and low preference is noted in the girder bridge. In conclusion, the visual preference of bridge landscape depend on the background and bridge shape, the study said. Therefore, when bridge designer design the bridge, designer have to choose proper bridge shape according to the background. This research was conducted only in bridge landscape of rural area but the visual preference of bridge landscape can be changed according to the various background. And further research is needed to analyze visual preference of bridge landscape according to the various background.

An Extension Method of IFC Model for Representing Design Information of Steel Bridge Members (강교 부재의 설계정보 표현을 위한 IFC 모델의 확장 방안)

  • Yi, Jin-Hoon;Huang, Meng-Gang;Lee, Ji-Hoon;Lee, Sang-Ho
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • pp.524-531
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    • 2008
  • A method for representing detailed design information of steel bridge member is proposed on the basis of the IFC model. As a first step, bridge related entities in the IFC-BRIDGE V2 and their functions are analyzed. In addition, design documents of steel bridge members are analyzed to extract information items that are not handled in the IFC-BRIDGE V2. It is recommended that several entities in the IFC-BRIDGE V2, such as ifcBridgeFibre, IfcBridgeReferenceLine, and IfcBridgeSection, should be properly relocated. In addition, IfcBridgeStiffener, IfcBridgeJointSystem, IfcBridgeDiaphragm, and IfcBridgeShearConnector are added as subtypes of IfcBridgeElementComponent for representing the stiffener, joint system, diaphragm, and shear connector, respectively. The added new entities inherit all attributes of IfcProduct which is linked with other resources: geometric representation, placement, material information, and so on. Thus, it is considered that a proposed in-depth IFC-BRIDGE model can be used more widely.

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Wake effects of an upstream bridge on aerodynamic characteristics of a downstream bridge

  • Chen, Zhenhua;Lin, Zhenyun;Tang, Haojun;Li, Yongle;Wang, Bin
    • Wind and Structures
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    • v.29 no.6
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    • pp.417-430
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    • 2019
  • To study the wake influence of an upstream bridge on the wind-resistance performance of a downstream bridge, two adjacent long-span cable-stayed bridges are taken as examples. Based on wind tunnel tests, the static aerodynamic coefficients and the dynamic response of the downstream bridge are measured in the wake of the upstream one. Considering different horizontal and vertical distances, the flutter derivatives of the downstream bridge at different angles of attack are extracted by Computational Fluid Dynamics (CFD) simulations and discussed, and the change in critical flutter state is further studied. The results show that a train passing through the downstream bridge could significantly increase the lift coefficient of the bridge which has the same direction with the gravity of the train, leading to possible vertical deformation and vibration. In the wake of the upstream bridge, the change in lift coefficient of the downstream bridge is reduced, but the dynamic response seems to be strong. The effect of aerodynamic interference on flutter stability is related to the horizontal and vertical distances between the two adjacent bridges as well as the attack angle of incoming flow. At large angles of attack, the aerodynamic condition around the downstream girder which may drive the bridge to torsional flutter instability is weakened by the wake of the upstream bridge, and the critical flutter wind speed increases at this situation.

Dynamic analysis of long-span cable-stayed bridges under wind and traffic using aerodynamic coefficients considering aerodynamic interference

  • Han, Wanshui;Liu, Huanju;Wu, Jun;Yuan, Yangguang;Chen, Airong
    • Wind and Structures
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    • v.24 no.5
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    • pp.405-430
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    • 2017
  • The aerodynamic characteristics of vehicles are critical to assess vehicle safety and passenger comfort for vehicles running on long span bridges in a windy environment. However, in previous wind-vehicle-bridge (WVB) system analysis, the aerodynamic interference between the vehicle and the bridge was seldom considered, which will result in changing aerodynamic coefficients. In this study, the aerodynamic coefficients of a high-sided truck on the ground (ground case) and a typical bridge deck (bridge deck case) are determined in a wind tunnel. The effects of existent structures including the bridge deck and bridge accessories on the high-sided vehicle's aerodynamic characteristics are investigated. A three-dimensional analytical framework of a fully coupled WVB system is then established based on the finite element method. By inputting the aerodynamic coefficients of both cases into the WVB system separately, the vehicle safety and passenger comfort are assessed, and the critical accidental wind speed for the truck on the bridge in a windy environment is derived. The differences in the bridge response between the windward case and the leeward case are also compared. The results show that the bridge deck and the accessories play a positive role in ensuring vehicle safety and improving passenger comfort, and the influence of aerodynamic interference on the response of the bridge is weak.

Deflection Limit on Vibration Serviceability of High-speed Railway Bridges Considering the Exposed Time Duration (진동지속시간을 고려한 고속철도교량의 진동 사용성 처짐 한계)

  • Jeon, Bub-Gyu;Kim, Nam-Sik;Kim, Sung-Il
    • Proceedings of the KSR Conference
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    • pp.1444-1451
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    • 2010
  • This paper aims for proposed the deflection limit on vibration serviceability of high-speed railway bridges considering the exposed time duration when a train passes a railway bridge. For this purpose, bridge-train transfer function was derived and bridge-train interaction analysis was performed by using the derived function. The vertical acceleration signals of passenger cars obtained from bridge-train interaction analysis were compared with them from the bridge-train transfer function by moving constant force analysis. Therefore it was estimated possible to induce the comfort deflection limit of railway bridge by using bridge-train transfer function. The deflections by moving force of single span bridge and continuous bridge were assumed as sine and haversine wave. The deflection limit on vibration serviceability of high-speed railway bridges considering the exposed time duration can be expanded using bridge-train transfer function and bridge comfort limit considering serviceability due to bridge vibration. And it was compared to other allowable deflection limits of railway bridge design specifications.

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Variability in bridge frequency induced by a parked vehicle

  • Chang, K.C.;Kim, C.W.;Borjigin, Sudanna
    • Smart Structures and Systems
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    • v.13 no.5
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    • pp.755-773
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    • 2014
  • The natural frequency of a bridge is an important parameter in many engineering applications such as bridge seismic design and modal-based bridge health monitoring. The natural frequency of a bridge vibrating alone may differ from that vibrating along with a vehicle. Although such vehicle-induced variability in bridge frequency is revealed in several experimental and numerical simulation studies, few attempts have been made on the theoretical descriptions. In this study, both theoretically and experimentally, the variability in the bridge frequency induced by a parked vehicle is verified, and is therefore suggested to be considered in bridge-related engineering, especially for those cases with near vehicle-bridge resonance conditions or with large vehicle-to-bridge mass ratios. Moreover, the variability ranges could be estimated by an analytical formula presented herein.

Investigation on mechanics performance of cable-stayed-suspension hybrid bridges

  • Zhang, Xin-Jun
    • Wind and Structures
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    • v.10 no.6
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    • pp.533-542
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    • 2007
  • The cable-stayed-suspension hybrid bridge is a cooperative system of the cable-stayed bridge and suspension bridge, and takes some advantages and also makes up some deficiencies of both the two bridge systems, and therefore becomes strong in spanning. By taking the cable-stayed-suspension hybrid bridge, suspension bridge and cable-stayed bridge with main span of 1400 m as examples, the mechanics performance including the static and dynamic characteristics, the aerostatic and aerodynamic stability etc is investigated by 3D nonlinear analysis. The results show that as compared to the suspension bridge and cable-stayed bridge, the cable-stayed-suspension hybrid bridge has greater structural stiffness, less internal forces and better wind stability, and is favorable to be used in super long-span bridges.

Parameters influencing redundancy of twin steel box-girder bridges

  • Kim, Janghwan;Kee, Seong-Hoon;Youn, Heejung;Kim, Dae Young
    • Steel and Composite Structures
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    • v.29 no.4
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    • pp.437-450
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    • 2018
  • A bridge comprising of two girders, such as a twin steel box-girder bridge, is classified as fracture critical (i.e., non-redundant). In this study, the various bridge components of the twin steel box-girder bridge are investigated to determine if these could be utilized to improve bridge redundancy. Detailed finite-element (FE) models, capable of simulating prominent failure modes observed in a full-scale bridge fracture test, are utilized to evaluate the contributions of the bridge components on the ultimate behavior and redundancy of the bridge sustaining a fracture on one of its girders. The FE models incorporate material nonlinearities of the steel and concrete members, and are capable of capturing the effects of the stud connection failure and railing contact. Analysis results show that the increased tensile strength of the stud connection and (or) concrete strength are effective in improving bridge redundancy. By modulating these factors, redundancy could be significantly enhanced to the extent that the bridge may be excluded from its fracture critical designation.

Development of Bridge Scour Manual (교량세굴 평가 기술매뉴얼 개발)

  • Park, Jae-Hyeon;Lee, Ju-Hyung;Chung, Moon-Kyung;Kwak, Ki-Seok
    • Proceedings of the Korean Geotechical Society Conference
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    • pp.517-524
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    • 2004
  • The leading cause of bridge failures is scouring bed material from around bridge foundations. Many advanced countries such as U.S.A., U.K., the Netherlands and New Zealand have developed and revised their own bridge scour manuals fit for their field conditions. In Korea, researches for reducing bridge failures during floods have concentrated on analysis, laboratory test and countermeasure of bridge scour during the last ten years. however no comprehensive manual for evaluating bridge scour and for identifying the conditions of bridge foundations has been provided yet. In this study, a new bridge scour manual is developed for the accurate evaluation of bridge scour, which reflects domestic field conditions with various streambed materials. The SRICOS method and the Erodibility Index Method are suggested for fine-grained soils and weathered rocks, respectively. In addition, bridge scour analysis algorithms are developed for field engineers to estimate bridge scour depth and to evaluate the susceptibility of bridge scour with ease.

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