• Title/Summary/Keyword: pier

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Pier Scour Prediction in Pressure Flow

  • Choi, Gye-Woon;Ahn, Sang-Jin;Kim, Jong-Sup
    • Korean Journal of Hydrosciences
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    • v.6
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    • pp.23-37
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    • 1995
  • In this experimental paper, the maximum scour depth at pier was student. The model of the pier of San Gye bridge in the Bocheong stream was set for the experimental studies. Several model verification processes were conducted through the roughness comparisons between model and prototype, pursuing scour depth variations with time depending upon channel bed variation, the comparison of the ratios between falling velocities and shear velocities in the model and prototype, and the comparison of pier scour depths between experimental data and field measuring data. The experiments were conducted in the free flow conditions and pressure flow conditions. The maximum scour depth at piers in the pressure flow conditions is almost twice as much as compared to the free flow conditions. Also, the maximum scour depth variations are indicated in the figures based on the Froude numbers, opening ratios, water depths and approaching angles in the free surface flow conditions.

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Improvement of Constructability of Coping by Reduction of Reinforcement Amount (철근량 저감을 통한 코핑부 시공성 향상)

  • Park, Bong-Sik;Park, Sung-Hyun;Cho, Jae-Yeol
    • Proceedings of the KSR Conference
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    • 2011.10a
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    • pp.1577-1582
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    • 2011
  • Recently rapid construction of bridge is a main interest in construction. A research on rapid construction of pier coping is urgently needed because pier, which is a bridge understructure, directly affect lane reduction and increase of social cost. Precast assembly method and pre-assembly method are the main subjects of rapid construction. But these researches have focused not on reduction of reinforcement amount, but on modifying production method of coping. Reinforcement amount of design specification is as much as that of coping under constructing. So different approach is needed for reduction of reinforcement amount. In this paper, design of pier coping using strut-tie model was proposed for reduction of reinforcement amount and improvement of constructability. Railway bridge pier coping under constructing was analyzed using a finite element method and designed using strut-tie model.

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Seismic Analysis of a Bridge Using Fiber Element (섬유요소를 이용한 교량의 지진해석)

  • 조정래;곽임종;조창백;김병석;김영진
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2002.03a
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    • pp.151-158
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    • 2002
  • In the present design concept, the nonlinear behaviour of bridges is at lowed under large earthquake. The nonlinearity is, however, localized like pier, bearing, etc. Especially, pier columns are most important members for seismic performance. It is, however, difficult to solve the problem how the nonlinearity of columns should be modelled. In this study, the fiber element is used for modelling pier column. The element is a kind of structural elements like frame element, and it can model the distributed plasticity of plastic hinge. A 3 span continous bridge is taken for seismic analysis. First, the nonlinear static analysis the column at fixed support are performed so that the characteristics of column is analyzed. Second, Linear and nonlinear dynamic analysises using simplified model for longitudinal direction are carried out and the results are analyzed.

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A Parameter Study of Internally Confined Hollow Reinforced Concrete Piers (내부 구속 중공 RC 교각의 매개변수 연구)

  • Choi, Jun-Ho;Yoon, Ki-Yong;Han, Taek-Hee;Kang, Young-Jong
    • 한국방재학회:학술대회논문집
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    • 2007.02a
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    • pp.59-62
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    • 2007
  • The hollow RC(Reinforced concrete) pier has decrease of weight and reduced of materials compared to solid RC pier. However, the hollow RC pier shows a low ductile behavior due to brittle failure of inside concrete. To overcome this problem, the internally confined hollow reinforced concrete column has been developed. In this study, the behavior of internally confined hollow RC piers were evaluated with safety ratio, ductility, total material cost, the total weight of the pier, etc. The chosen parameters for the study are hollow ratio, thickness of internal steel tube, intervals between vertical re-bars, numbers of horizontal re-bars, and strength of concrete.

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Armouring Effect on Local Scour around Bridge Piers (교각의 세굴에 미치는 Armouring 효과)

  • 이종규
    • Water for future
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    • v.26 no.4
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    • pp.107-115
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    • 1993
  • The results of laboratory experiments on the clear-water local scour of cohesionless bed sediment at three types of the pier shape are presented. Based on the experimental data, the relative equilibrium depth of local scour is related to the pier shape, the geometric standard deviation of the bed material, the velocity ratio and the pier Froude number. The relative local scour depths were smallest ant the round-nosed pier and remarkably reduced at the non-uniform bed sediment, comparing with those at the uniform bed material. The effect of sediment grading on the local scour reduction was discussed and compared with Raudkivi and Ettema's experiments.

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The Evaluation of reinforcing method for the pier foundations on the karstic areas containing the solution cavities in Korea (국내의 석회암 공동지역 기초지반보강법에 대한 평가)

  • Im, Soo-Been;Noh, Seung-Han;Jegal, Ho
    • Proceedings of the Korean Geotechical Society Conference
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    • 2005.10a
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    • pp.499-509
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    • 2005
  • We have many foundations which were constructed on the karstic areas where solution cavities and fractured zone may form under, or close to foundations. The fact that the ground under the pier foundations was reinforced with the three axial high pressure jet grouting is confirmed through out about two hundred design reports. It is necessary that evaluation of a simple application of high pressure jet grouting method on the karstic areas containing solution cavities. In this study, the improved situation and reinforcing methods of the ground under the pier foundations are proposed based on the evaluation of design reports for the express highway and No.38 national roads.

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The Comparison of Strength of pier in Different provisions (비보강 조적조 기준들의 강도식 비교)

  • 김홍범;이준석;한상환
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2001.04a
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    • pp.312-319
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    • 2001
  • The purpose of this study is to evaluate the strength of piers subjected to earthquake ground motion. In particular, the piers of an unreinforced masonry wall under in-plane seismic loading are considered with emphasis. For this purpose, several pier strength equations in seismic rehailitation provisions such as UCBC, FEMA 178, FEMA 273, and FEMA 306 are compared. This strength equations in different provision are applied for calculating the strength of a pier in building. According to the results of this study, it is shown that the assessment procedure based on FEMA 178 overestimated pier strengths comparing to other provisions when all piers are in Rocking-controlled mode.

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New Hollow RC Bridge Pier Sections with Triangular Reinforcement Details: II. Parametric Study (삼각망 철근상세를 갖는 새로운 중공 철근콘크리트 교각단면: II. 매개변수 연구)

  • Kim, Tae-Hoon;Kim, Ho-Young;Son, Je-Kuk
    • Journal of the Earthquake Engineering Society of Korea
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    • v.19 no.3
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    • pp.121-132
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    • 2015
  • The purpose of this study is to investigate the behavior characteristics of new hollow reinforced concrete (RC) bridge pier sections with triangular reinforcement details and to provide the details and reference data. Among the numerous parameters, this study concentrates on the shape of the section, the reinforcement details and the spacing of the transverse reinforcement. Additional eight column section specimens were tested under quasi-static monotonic loading. In this study, the computer program, named RCAHEST (Reinforced Concrete Analysis in Higher Evaluation System Technology), was used. A innovative confining effect model was adopted for new hollow bridge pier sections. This study documents the testing of new hollow RC bridge pier sections with triangular reinforcement details and presents conclusions based on the experimental and analytical findings.

Influence of Pile Cap's Boundary Conditions in Piled Pier Structures (교량 말뚝기초의 단부 지점조건의 영향분석)

  • Jeong, Sang-Seom;Won, Jin-Oh
    • Proceedings of the Korean Geotechical Society Conference
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    • 2005.03a
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    • pp.25-32
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    • 2005
  • Modeling techniques of piled pier were reviewed and the influences of pile cap's boundary conditions were analyzed in this study. Among various modeling techniques, equivalent cantilever method seems relatively simple for modeling pile groups and it has some problems to determine the virtual fixed points. Through the analyses, it was found that the method of nonlinear p-y model with soil springs was more appropriate than equivalent cantilever method. The method modeling a pile group using stiffness matrix seems useful for practical design, which can represent the nonlinear three-dimensional behavior of a piled pier. In this study, the stiffness matrix of a pile group could be estimated efficiently and precisely using three-dimensional nonlinear analysis programs of pile groups (FBPier 3.0, YSGroup).

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Information Modeling of Modular Bridge Pier using BIM Based 3D-Model Library (BIM 기반 3차원 모델 라이브러리를 통한 모듈러 교각의 정보모델링)

  • Jo, Jae-Hun;Kim, Dong-Wook;Lee, Kwang-Myong;Nam, Sang-Hyeok
    • Journal of KIBIM
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    • v.3 no.4
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    • pp.11-18
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    • 2013
  • Modular technology has become a major issue of the construction industries to enhance their productivity. Modular bridge construction generally requires the collaboration between the contractor, designer, fabricator and constructor. Therefore, a readily accessible information model based on BIM technology should be provided for their communication during a construction project life-cycle. In this study, BIM based 3D information modeling was carried out for the modular bridge pier. First, the product breakdown structure (PBS) and level of detail (LOD) of the pier were defined. Based on them, 3D models were created by using parametric modeling method. In addition, database was constructed for the exchange of geometry and property data of 3D models. Finally, application areas of 3D information model were suggested, including the quantity estimation and the 4D simulation.