• Title/Summary/Keyword: Piers shape

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Arrangement of Connections and Piers and Earthquake Resistant Capacity of Typical Bridges (연결부분 및 교각의 배열과 일반교량의 내진성능)

  • Kook, Seung-Kyu
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.28 no.2
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    • pp.207-212
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    • 2015
  • Bridges are designed and constructed as infrastructures in order to overcome topographical obstructions for fast and smooth transfer of human/material resources. Therefore the shape and size of piers constructed along the longitudinal bridge axis should be restricted by topographical conditions. Action forces of connections and piers are affected by pier shapes and sizes together with connection arrangement which decides load carrying path under earthquakes. In this study a typical bridge is modelled with steel bearings and reinforced concrete piers and seismic analyses are performed with analysis models with different arrangement of steel bearings and piers. From analysis results ductile failure mechanisms for all analysis models are checked based on strength/action force ratios of steel bearings and pier columns. In this way the influences of arrangement of connections and piers on the earthquake resistant capacity of typical bridges are figured out in view of forming ductile failure mechanism.

Development of Creative Design and Construction Methods of Bridge Piers using 3D Model (3차원 모델 기반의 미적 교각 설계 및 시공 기술 개발)

  • Lee, Sang-Yong;Dong, Ngoc Son;Shim, Chang-Su
    • Journal of KIBIM
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    • v.5 no.2
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    • pp.12-18
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    • 2015
  • Bridge piers typically have circular or rectangular shapes without decorative design. Prefabrication for accelerated construction has been widely adopted in bridge structures. Cost for steel formwork is a main restriction of creative irregular shapes. 3D modelling techniques allow creative design of columns and 3D printing provides possibility to minimize the fabrication cost. In this paper, 3D design process of bridge piers was suggested by converting 2D picture into 3D decorative shape. Formwork design using 3D printed panels was also proposed and mock-up tests were conducted. Precast columns need accurate geometry control from fabrication to assembly. Laser scanning and geometry control devices were adopted. Through the digitalized process of design, fabrication and assembly, creative design of structures can be realized in reasonable cost range.

Anti-Seismic of Existing Bridge Pier by Nickel-chrome Alloy Bar (니켈-크롬 합금강바를 이용한 기존 교각부의 내진보강)

  • Jang, Il-Young;Song, Seok-Min;Yoo, Jeong-Soo;Son, Chang-Ho;Son, Deok-Jong
    • Proceedings of the Korea Concrete Institute Conference
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    • 2010.05a
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    • pp.131-132
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    • 2010
  • Seismic design for new built bridges has been considered which is being used now. However, before the revised code for seismic design is issued, the reinforced concrete bridge piers which has been built and being used are pretty weak under the lateral seismic load. experiments of bridge piers are done under iterative lateral load, according to experimental results, the influence of Nikon-Chrome alloy steel barson performance of bridge piers is analyzed, also the shape effect of anti-seismic reinforcement on pier behavior is discussed.

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TIME EVOLUTION OF SCOUR AROUND BRIDGE ABUTMENTS

  • Francesco Ballio;Enrico Orsi
    • Water Engineering Research
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    • v.2 no.4
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    • pp.243-259
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    • 2001
  • Local phenomena around bridge piers and abutments are generally considered to be similar, nevertheless the presence of the incoming boundary layer on the side wall in the abutment case generates extra pressure gradients and consequently a more complex vortex pattern. In the literature, experimental data for bridge abutments are relatively scarce; in particular almost no data are available for the time evolution of the scour. In this work we present the results of several long duration (3 days longrightarrow5weeks) clear water scour laboratory tests around bridge abutments; the time evolution of the erosion process is analysed with respect to local and global characteristic values (maxima, volume, hole shape). In particular we analyse the effect of the constriction ratio b/B between the transversal obstacle dimension and the flume width: in many practical situations abutments (or piers) obstruct a significant portion of the channel, so that the average acceleration due to constriction is expected to increase the scour effects of the local acceleration around the obstacle. Measured values for maximum scour are poorly predicted by literature formulas. Scour depths are positively correlated with the constriction ratio, but increases are smaller than expected from literature indications. Experimental results show that models for bridge piers cannot be directly applied to abutments; in particular, time scales for the latter are significantly larger than for piers.

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Hydraulic Analysis Using a Two-Dimensional Model(I) : Flow Analysis around Bridge Piers with Pier Shapes (2차원 모형을 이용한 수리해석(I) : 교각형상별 주변부 흐름해석)

  • Kim, Eung-seok;Lee, Seung-hyun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.7
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    • pp.4936-4941
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    • 2015
  • This study(I) has analyzed hydraulic characteristics with pier shapes by the bridge construction. The pier shapes are classified into total six types such as square, rhombus, octagon, oval, round, and no-piers. One-dimensional model(HEC-RAS) and two-dimensional model (RMA-2) were employed to analyze hydraulic characteristics around bridge piers. Square and rhombus shapes of piers showed velocity vectors in the upstream direction, which has a significant impact on the river bed changes by erosion and sediment transport around the piers. The flow characteristics of the oval type pier was most similar to that of no-pier situation almost without disrupting the river flow. This analysis can help to select pier types in the new bridge construction for the future.

Seismic Retrofit of RC Columns with Lap-Spliced Longitudinal Rebars Wrapping by SMA Wires (SMA Wire를 이용한 주철근 겹침이음된 RC 교각의 내진 보강 연구)

  • Park, Yong-Kwon;Lee, Yeon-Hun;Yang, Dong-Wook;Lim, Hyeon-Sik;Chung, Young-Soo
    • Proceedings of the Korea Concrete Institute Conference
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    • 2010.05a
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    • pp.129-130
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    • 2010
  • Lap splice of longitudinal reinforcing steels was located in the plastic hinge region of most bridge piers that had been designed and constructed before the adoption of the 1992 seismic design provision of Korea Highway Design Specification. This research aims at improving the seismic performance of reinforced concrete bridge piers with lap-spliced longitudinal steels, of which the plastic hinge region was wrapped by the shape memory alloy (SMA) wires. Quasi-static test was used to investigate the seismic behaviours of RC test specimens.

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Inelastic Behavior of the SRC Column (SRC 합성교각의 비탄성 거동)

  • Jung, In-Keun;Min, Jin;Shim, Chang-Su;Chung, Young-Soo
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2005.03a
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    • pp.300-307
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    • 2005
  • Steel Reinforced Concrete (SRC) composite column has several advantage such as excellent durability, rapid construction, reduction of column section. Due to these aspect, applications of SRC columns to bridge piers are continuously increasing. For the design of relatively large SRC columns for bridge piers, it is necessary to check the current design provisions which were based on small section having higher steel ratio. In this study, seven concrete encased composite columns were fabricated and static tests were performed. Embedded steel members were a H-shape rolled beam and a partially filled steel tube. Based on the test results, the ultimate strength according to section details and local behavior were estimated. For the analysis of inelastic behavior of the SRC column, the cracked section stiffness of the columns was evaluated and compared with calculations. The stiffness of the cracked section showed that 25% of the initial value and this stiffness reduction occurred at 85% of the ultimate load in the experiments.

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A Study of the Local Scour Considering the Pier Shapes in the Cohesive Bed (점착성 하상에서의 교각형상에 따른 국부세굴 연구)

  • Choe, Gye-Un;Kim, Gi-Hyeong
    • Journal of Korea Water Resources Association
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    • v.31 no.5
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    • pp.539-552
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    • 1998
  • When the pier is constructed in the cohesive be, the accuracy maynot be obtained because the equation for calculating the scour at piers is based upon the results which are analyzed through the experiments in the non-cohesive bed. In this paper, the variation of the depth of the pier scour occurred by constructing 5 types of pier in the channel having the cohesive material is examined. The experimental results are analyzed based upon Froude numbers and non-dimensional numbers which are indicated as the flow depths compared to the pier width. The results are also compared with the results obtained using the existing pier scour equations. In this paper, the shape factors, which can be used for calculating the scour depth of the pier in the cohesive channel bed, are suggested. The shape factors are indicated through the ratios between the scour depth at the circular pier and the scour depths at the different types of pier, and are suggested as two stages. In the first stage, in which the water depth compared to the pier width is less than 1.2, the shape factors are given as the equations. However, in the second stage the shape factors are given as the constant values. It is understood that the shape factors suggested in this paper can be properly usd for calculating local scour at piers in the bridges which are constructed in the cohesive channel bed having the characteristics of the bed material which is used in these experiments. Keywords : local scour, maximum scour depth, cohesive bed material, pier shape, pier, shape factor.

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Analysis of Intercepted Flow Characteristics by Accumulated Debris (부유잡목에 의한 흐름차단이 하천에 미치는 영향 분석)

  • Choi, Gye-Woon;Kim, Young-Gyu;Hwang, Young-Man;Cho, Sang-Wook
    • Proceedings of the Korea Water Resources Association Conference
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    • 2007.05a
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    • pp.846-850
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    • 2007
  • In this study debris like branch or trash are washed and flowed from land to stream by rainfall runoff at mountain or urban stream specially rainy season. These kinds of debris are accumulated at hydraulic construct on the way of flow along the stream. The shape or ratio of like these accumulated debris are various according to the location where it is accumulated and the material what it is, so that it is influenced to be varied to flow characteristics. To be simple of accumulated debris shape, it was made experiments though the variation of open ratio and the shape of accumulated debris by lab experiment using straight channel with two piers. From the result, the water level is inverse proportion to open ratio, and the water level more sensitive to the debris‘ width than length at the same area of accumulated debris.

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Experimental and numerical study of Persian brick masonry barrel vaults under probable structural hazards

  • Saeid Sinaei;Esmaeel Izadi Zaman Abadi;Seyed Jalil Hoseini
    • Structural Engineering and Mechanics
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    • v.87 no.4
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    • pp.317-332
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    • 2023
  • Understanding and analysing the behaviour and response of historical structures in the face of climate changes and environmental conditions is of utmost significance for their preservation. There are several structural hazards associated with climate and hydrology changes in the region, including the settlement of piers, the rotation of piers, and temperature changes. The present study investigates the experimental and numerical structural behaviour of skewed and non-skewed Persian brick masonry barrel vaults under various conditions. The external loading conditions included pier rotation in five modes, settlement, and temperature variations in four states. Initially, the experiments extracted the mechanical properties of the scaled materials. Then, three semi-circular brick barrel vaults were tested with gravitational loads. The outcomes were used to develop and validate the finite element model. Following the development of the finite element model, numerical and parametric studies were conducted on the effect of the aforementioned structural hazards on the response of brick masonry barrel vaults with various Persian geometries (semi-circular, drop pointed, and four-centred), angles of skew (0, 15, 30, and 45 degrees), and dimensional ratios. According to the findings, the fragility of masonry materials makes historical structures susceptible to failure under different loading. A brick barrel vault fails in the presence of minor rotation and settlement of the piers. The four-centred geometric shape has the lowest performance among the seven Persian geometries; therefore, its health monitoring and retrofitting should be prioritised. In Isfahan, Iran, temperature variations, particularly during the warm seasons, cause critical conditions in such structures.