• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2002년도 봄 학술발표회 논문집
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• pp.531-536
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• 2002

The design of anchorage zone in prestressed concrete cable stayed bridges is very important area due to the more accurate analysis is needed to estimate the behavior. In the study, since the cable anchorage zone in the prestressed concrete cable-stayed bridge is subject to a large amount of concentrated tendon forces, it shows very complicated stress distributions and causes a serious local cracks. Accordingly, It is necessary to investigate the parameters of affecting the stress distribution, such as the cable inclination, the position of anchor plate, the modeling method and the three dimensional effect. The tensile stress distribution of anchorage zone is compared to the actual design condition by varing the stiffness of spring element in the local modeling and an appropriate position of anchor plate is determined. These results would be elementary data to the stress state of anchorage zone and more efficient design.

• Structural Engineering and Mechanics
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• 제16권1호
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• pp.1-15
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• 2003

This paper proposes a new method for the preliminary design of cable-stayed bridges that belong to the radial system subjected to static loads (self weight, traffic loads, concentrated loads, etc). The method is based on the determination of the each time existing relation between the tension forces of the cables and the corresponding bridge-deck deformations, and can be extended on any type of cable layout (fan, parallel, or mixed system). Galerkin's method is used for the final determination of the cable stresses and the bridge deformation. The determination of the equation, which gives the forces of the cables in relation to the deck's configurations, permits us to convert the problem to the solving of a continuous beam without cables.

• Computers and Concrete
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• 제13권4호
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• pp.483-499
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• 2014

Most of the methods presented in the literature to define the target service stresses (Objective Service Stage, OSS) of cable-stayed bridges rarely include the time-dependent phenomena effects. Nevertheless, especially in concrete structures, this assumption might be on the unsafe side because time-dependent phenomena usually modify service stresses. To fill this gap, this paper studies the time-dependent phenomena effects into service stresses of concrete cable-stayed bridges. After illustrating the important role of these phenomena in an asymmetrical cable-stayed bridge without backstay, a new method to include their effects into the OSS is presented. An important issue to be considered in this method is the target time in which the OSS is defined to be achieved. The application of this method to two different structures showed the convenience of defining the OSS to be achieved at early times because that way the envelope of service stresses is reduced.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 가을 학술발표회 논문집
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• pp.615-620
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• 2001

The aim of this paper is to open up a relatively new type in bridge engineering by introducing plan and design of extradosed bridge which is implemented in Sungnam-Janghowon T/K project. The topic encompasses parametric study including the behavior of the bridge relevant to the cable layout, the distance from pier table to the first cable's location, the height of pylon, the stiffness of cross section and wind vibration to ascertain sectional type of bridge and span length. For the purpose of the knowledge base presented here, the important feature of design is recommended such as modeling method, camber control, finite element analysis and heat hydration of pier table. We can verify the issue related to the characteristics of extradosed bridge as a result of study and design endeavor.

• 한국안전학회지
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• 제25권6호
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• pp.146-154
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• 2010

In this study the experimental results of fatigue specimen for the Strand Stay Cable Assembly of Extadosed bridges is investigated. The fatigue test and tensile experiment is conducted to 6 kinds of specimens. Test specimen OVM250-31 Strand Cable System manufactured by china OVM B-Machinery Co., Ltd, and OVM250-42 Parallel Strand Stay Cable Assembly manufactured by china OVM B-Machinery Co., Ltd, are passed for fatigue test and rupture tensile test. But Test specimen OVM250-42 Parallel Strand Stay Cable Assembly manufactured by korean A-Machinery Co., Ltd, is not passed for fatigue test conducted according to the "Recommendation for Stay Cable Design. The test result are compared to the fatigue criteria of PHI 2001 for cyclic load, and it is concluded that the current korean design code will be needed for representing the fatigue load in Hot Dip Galvanized Strand Stay Cable. It is verified that the new korean specification and quality criteria of Strand Stay Cable and exact experimental applied process will be needed.

• 한국강구조학회 논문집
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• 제19권1호
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• pp.1-13
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• 2007

강사장교의 거더와 주탑은 축력과 모멘트를 동시에 받는 보-기둥 부재이기 때문에 단일 힘을 고려하는 일반도로교의 내하율 산정식은 강사장교의 거더와 주탑에 적용할 수 없다. 현재, 사장교의 거더와 주탑에 적용 가능한 이론적인 내하율 산정방법은 아직 정립되지 않았다. 본 논문에서는 축력과 모멘트를 동시에 받는 부재의 상관공식을 적용하여 강사장교 거더와 주탑의 내하율을 산정하기 위한 식을 제안하였다. 영향선해석을 수행하여 각 부재에 압축력 최대, 정 및 부모멘트 최대의 경우에 활하중 재하 형태를 결정하였고 각 부재의 내하율 산정절차를 정리하였다. 제안된 내하율 산정방법의 타당성을 검증하기 위하여 실교량 모델인 돌산대교에 대한 적용예를 제시하였다. 일반도로교의 내하율 산정식은 돌산대교 거더와 주탑의 내하율을 과대평가 하였으며, 제안된 내하율 산정식은 축력과 모멘트를 동시에 지지하는 사장교 거더와 주탑의 거동을 적절히 반영하였다.

• 한국구조물진단유지관리공학회 논문집
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• 제15권4호
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• pp.212-220
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• 2011

최근 들어 인천대교 등 다수의 사장교가 공용 또는 시공 중에 있으며 이러한 시점에서 국내 사장교의 기술력을 살펴본다면 시공기술은 눈에 띄게 발전하였지만 설계기술은 아직 국외 의존도가 매우 높은 실정이다. 사장교 핵심설계요소들 중 케이블 정착구조는 강력한 케이블 장력의 작용으로 국부적인 응력집중현상이 발생하므로 안전성 확보를 위해서는 반드시 국부상세해석에 의한 설계가 요구된다. 하지만 명확한 설계기준이나 이론적 설계 없이 유한요소해석에만 의존하여 설계하는 실정이며 정착구조의 이론적 기본메커니즘을 이해하지 못한 채 유한요소해석 결과에만 의존, 엔지니어의 판단력이 흐려지는 부작용을 가져오고 있다. 이에 따라 본 연구에서는 케이블 정착구조 가이드 파이프앵커 형식 중 정착강관의 기존 이론적인 설계절차를 나타내고 추가적으로 고려해야 할 사항들을 국내외 설계기준에 따라 정리하고 보완 설계절차를 제시하였다.

• 복합신소재구조학회 논문집
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• 제4권4호
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• pp.30-36
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• 2013

Partially earth anchored (PEA) can improve the structural safety and economic feasibility of multiple span cable stayed bridge (CSB). The PEA-CSB can restrain axial compressive load acting on a tower and reduce the global buckling length of a stiffened girder. For these reasons, structural members subject to axial forces can be effectively utilized and material quantity required for a steel deck can be reduced to save construction cost. In this study, the PEA system was verified for its application on a multiple span CSB. The CSB is a four-tower multi-span bridge which has a main span length of 500 m. As high tensile stress was generated at the top of the bridge decks at the mid-span between two main columns, a hybrid deck system for enhancing the bridge deck sections was proposed. While the composite sections made of concrete and steel were used near to the main columns, steel sections were used at the mid-span between two main columns.

• Wind and Structures
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• 제13권4호
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• pp.309-326
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• 2010

CFD techniques try to find their way in the bridge engineering realm nowadays. However, there are certain fields where they offer superior performance such as conceptual bridge design and bidding design. The CFD studies carried out for the conceptual design of a 425 m length cable-stayed bridge are presented. A CFD commercial package has been employed to obtain for a set of cross-sections the aerodynamic coefficients considering 2D steady state. Additionally, for those cross-sections which showed adequate force coefficients, unsteady 2D simulations were carried out to detect the risk of vortex shedding. Based upon these computations the effect on the aerodynamic behavior of the deck cross-section caused by a number of modifications has been evaluated. As a consequence, a new more feasible cross-section design has been proposed. Nevertheless, if the design process proceeds to a more detailed step a comprehensive set of studies, comprising extensive wind tunnel tests, are required to better find out the aerodynamic bridge behavior.

• Smart Structures and Systems
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• 제17권3호
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• pp.413-429
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• 2016

The recent research on proper orthogonal decomposition (POD) has revealed the linkage between proper orthogonal modes and linear normal modes. This paper presents an investigation into the modal identifiability of an instrumented cable-stayed bridge using an adapted POD technique with a band-pass filtering scheme. The band-pass POD method is applied to the datasets available for this benchmark study, aiming to identify the vibration modes of the bridge and find out the so-called deficient modes which are unidentifiable under normal excitation conditions. It turns out that the second mode of the bridge cannot be stably identified under weak wind conditions and is therefore regarded as a deficient mode. To judge if the deficient mode is due to its low contribution to the structural response under weak wind conditions, modal coordinates are derived for different modes by the band-pass POD technique and an energy participation factor is defined to evaluate the energy participation of each vibration mode under different wind excitation conditions. From the non-blind datasets, it is found that the vibration modes can be reliably identified only when the energy participation factor exceeds a certain threshold value. With the identified threshold value, modal identifiability in use of the blind datasets from the same structure is examined.