• Title/Summary/Keyword: bridges construction

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Load-Displacement Characteristics Study of Barrette Pile by Bi-directional Loading Test (양방향재하시험을 통한 바렛말뚝의 하중-침하특성 연구)

  • Lim, Dae-Sung;Park, Seong-Wan;Lee, Sang-Rae
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.10a
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    • pp.754-759
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    • 2008
  • Recently, the construction of buildings and large bridges has been increasing rapidly causing foundation structure growing larger then before, especially in the use of large size cast-in-place piles. Barrette Pile will usually be used at the site where diaphragm wall is the retaining wall to save time and cost in mobilization of equipments. This study uses bi-directional loading test data obtained from two different sites to observe the bearing capacity and displacement characteristics of barrette pile. Numerical analysis of the test is done by using commercial 3D computer program and the interface effect and capacity of the pile as well as displacement characteristics of the pile is verified.

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A Study on Structural Function and Beauty of Stone Monuments as Landscape Elements (景觀構成要素로서의 石造形物의 造形美와 機能에 關한 硏究)

  • Lee, Jae-Ho
    • Journal of the Korean Institute of Landscape Architecture
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    • v.18 no.3 s.39
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    • pp.11-22
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    • 1990
  • Culture has long been associated with and advanced by stone as observed in prehistoric dolmen, menhir, megalith monuments, memo-rial stones, and others. The closs association of monuments is seen even in an earlist form of culture and is witnessed to evolve with human history. Korea, with its large quality granite repository, has been active with granite-based monuments in various forms of towers, bridges, and larterns. These stone structures are so abundant throughout Korea that Korea has been called the country of stone tower in Asia. With this historical background, we survey these Korean memorial stone and monuments, found at roadsides, momerial buildings, village entrances, scenic places, schools, sermon halls, public pleasure ground, and other common places. Based on installation orientation, location, and size, a particular emphasis is on the structural value, meaning, beauty, and function of these momnuments coupled with trees, shrubs, water and appropriative landscapes.

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Nonlinear analysis of connectors applied on concrete composite constructions

  • Winkler, B.;Bianchi, P.;Siemers, M.
    • Computers and Concrete
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    • v.3 no.2_3
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    • pp.91-102
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    • 2006
  • To place concrete overlays has become a standard application in the strengthening and rehabilitation of concrete structures such as bridges, tunnels, parking decks and industrial buildings. In general, connectors are used to ensure a monolithic behavior of the two concrete layers. Within the framework of the development of a new connector wedge splitting tests and shear tests were performed, in addition nonlinear finite element analyses were applied to investigate the load transfer behavior of the connectors for different prototypes. The numerical simulation results were compared to experimental data. The computed load-displacement curve demonstrates good correspondence with the curves obtained in the experiments, and the experimental crack patterns are reasonably simulated by the computed crack propagation. Both numerical and experimental investigations on the wedge splitting test and on the shear test served as basis for the development of new type of connectors.

Static Behavior of Prestressed Steel-Concrete Composite Girder (프리스트레스트 강합성 거더의 정적거동 평가)

  • Lee Pil-Goo;Kim Sung-Il;An Hae-Young;Moon Jong--Hoon
    • Proceedings of the KSR Conference
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    • 2005.11a
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    • pp.240-245
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    • 2005
  • There has been a strong demand on more economic and lower depth girder bridges for short and medium span range, PRECOM, which is a new type steel-concrete composite girder, has been developed to realize a more economic bridge system with a lower depth girder. In the PRECOM girder bridge, a steel plate girder is simply supported and then concrete form is hung to girder. Thus, the self-weight of the concrete is loaded to the steel girder. To increase the resistance of concrete in the lower casing against tensile stress, compressive force is introduced by prestressed tendon To evaluate the manufacturability and performances of the completed bridge, four 15-m girders and a bridge specimen with two 20m girders wvere constructed. The camber during the construction and introduction of an appropriate compressive force was evaluated. Dynamic data were obtained through the modal testing of the completed girders. Static loading test was also conducted to examine cracks and evaluate the decrease in stiffness and failure behavior under extreme conditions.

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Simplified formulations for flutter instability analysis of bridge deck

  • Vu, Tan-Van;Kim, Young-Min;Han, Tong-Seok;Lee, Hak-Eun
    • Wind and Structures
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    • v.14 no.4
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    • pp.359-381
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    • 2011
  • This paper deals with the flutter instability problem of flexible bridge decks in the framework of bimodal-coupled aeroelastic bridge system analysis. Based on the analysis of coefficients of the polynomials deduced from the singularity conditions of an integral wind-structure impedance matrix, a set of simplified formulations for calculating the critical wind velocity and coupled frequency are presented. Several case studies are discussed and comparisons with available approximated approaches are made and presented, along with a conventional complex eigenvalue analysis and numerical results. From the results, it is found that the formulas that are presented in this study are applicable to a variety of bridge cross sections that are not only prone to coupled-mode but also to single-mode-dominated flutter.

A Study on Performance Elevation of the deteriorated Concrete Girder Bridge by Continuous and External Tendons (연속화와 외부 프리스트레스 도입에 의한 노후된 콘크리트 거더교의 성능향상에 관한 연구)

  • Park, Seung-Bum;Hong, Seok-Joo
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.4 no.2
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    • pp.159-166
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    • 2000
  • The development of external prestressing methods has been one of the major trends in the concrete bridge constructions over the past decades. One of the promising methods to enhance the flexural strength of a externally prestressed girder is to place the tendons with large eccentricities. The analysis and design of composite girders prestressed by external tendons involve difficulties related mainly to the position of anchorages and the construction sequences. This study was conducted on the concrete bridges reinforced by the continuous girders and the external prestressing. The test results in this study showed that the external prestressing of a composite girder increased the range of the elastic behavior, reduced deflections, increased ultimate strength, and added to the redundancy by providing the multiple stress paths.

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Optimum design of multi-span composite box girder bridges using Cuckoo Search algorithm

  • Kaveh, A.;Bakhshpoori, T.;Barkhori, M.
    • Steel and Composite Structures
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    • v.17 no.5
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    • pp.705-719
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    • 2014
  • Composite steel-concrete box girders are frequently used in bridge construction for their economic and structural advantages. An integrated metaheuristic based optimization procedure is proposed for discrete size optimization of straight multi-span steel box girders with the objective of minimizing the self-weight of girder. The metaheuristic algorithm of choice is the Cuckoo Search (CS) algorithm. The optimum design of a box girder is characterized by geometry, serviceability and ultimate limit states specified by the American Association of State Highway and Transportation Officials (AASHTO). Size optimization of a practical design example investigates the efficiency of this optimization approach and leads to around 15% of saving in material.

A Study on Evaluation Criteria for Infrastructure Importance regarding Earthquake (공공시설물 지진대응을 위한 중요도 평가기준에 관한 연구)

  • Park, Jae-woo;Kim, Seok
    • Journal of the Korean Society of Industry Convergence
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    • v.21 no.6
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    • pp.317-327
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    • 2018
  • The perception of earthquake in Korea has changed due to the earthquake that occurred in Gyeongju and Pohang, and the earthquake has become an important factor in infrastructure management. Damage to infrastructures in the event of an earthquake is extensive. In particular, damage to infrastructures that perform public function used to spread to the whole area. From the point of view of earthquake disaster prevention, it is very important for the public to define what infrastructures are important management targets and to prepare a countermeasure. In this study, we propose a method to evaluate the importance of infrastructure to effectively manage infrastructures for earthquakes. For this purpose, important factors for the railway bridges, power generation and electric power facilities, and apartment complexes are suggested. AHP analysis is conducted to suggest priorities. In addition, the evaluation criteria for infrastructure importance are presented.

Modeling the transverse connection of fully precast steel-UHPC lightweight composite bridge

  • Shuwen Deng;Zhiming Huang;Guangqing Xiao;Lian Shen
    • Advances in concrete construction
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    • v.15 no.6
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    • pp.391-404
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    • 2023
  • In this study, the modeling of the transverse connection of fully precast steel-UHPC (Ultra-High-Performance Concrete) lightweight composite bridges were conducted. The transverse connection between precast components plays a critical role in the overall performance and safety of the bridge. To achieve an accurate and reliable simulation of the interface behavior, the cohesive model in ABAQUS was employed, considering both bending-tension and compression-shear behaviors. The parameters of the cohesive model are obtained through interface bending and oblique shear tests on UHPC samples with different surface roughness. By validating the numerical simulation against actual joint tests, the effectiveness and accuracy of the proposed model in capturing the interface behavior of the fully precast steel-UHPC lightweight composite bridge were demonstrated.

Experimental and analytical study on prestressed concrete hollow slabs with asymmetric boundary conditions

  • Ma, Haiying;Lai, Minghui;Xia, Ye
    • Structural Engineering and Mechanics
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    • v.81 no.1
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    • pp.59-68
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    • 2022
  • Prestressed prefabricated hollow core concrete slabs with spans of 5 m and 10 m are commonly used since last century and still in service due to the advantage of construction convenience and durability. However, the end slabs are regularly subjected to cracks at the top and fail with brittleness due to the asymmetric boundary conditions. To better maintain such widely used type of hollow core slabs, the effect of asymmetric constraint in the end slabs are systematically studied through detailed nonlinear finite element analyses and experimental data. Experimental tests of slabs with four prestressed tendons and seven prestressed tendons with different boundary conditions were conducted. Results observe three failure modes of the slabs: the bending failure mode, shear and torsion failure mode, and transverse failure mode. Detailed nonlinear finite element models are developed to well match the failure modes and to reveal potential damage scenarios with asymmetric boundary conditions. Recommendations regarding ultimate capacity of the slabs with asymmetric boundary conditions are made to ensure a safe and rational design of prestressed concrete hollow slabs for short span bridges.