• Title/Summary/Keyword: ductility-based seismic design

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Ductility Demand based Seismic Design for RC Bridge Columns (철근콘크리트 교각의 연성요구량에 따른 내진설계)

  • 이재훈;손혁수;고성현;최진호
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2002.09a
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    • pp.316-321
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    • 2002
  • The current seismic design criteria of the Korea Design Specifications for Highway Bridge (KDSHB 2000) adopted the seismic design concept and requirements of the AASHTO specifications. In order to obtain full ductile behavior under seismic loads, i.e. when applied seismic force is larger than design flexural strength of column section, a response modification factor is used. For the moderate seismicity regions, a design based on required ductility and required transverse reinforcement might be a reasonable approach. Ductility demand design or performance based design might be an appropriate approach especially for regions of moderate seismic risk. The procedure and application of this design approach are presented in this paper.

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New Seismic Design Concept for RC Bridge Columns

  • Lee, Jae-Hoon;Son, Hyeok-Soo
    • Proceedings of the Korea Concrete Institute Conference
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    • 2003.05a
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    • pp.204-209
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    • 2003
  • The purpose of this study is to develop new seismic design concept based on ductility demand for reinforced concrete bridge columns in areas of low to moderate seismicity. In developing the ductility based design approach, relationship between ductility demand and transverse reinforcement demand should be quantitatively developed. To evaluate ductility capacity of reinforced concrete columns, analytical models and a non-linear analysis program, NARCC have been developed. Based on analytical and experimental results, an equation for relationship between curvature ductility and displacement ductility, an equation for designing the transverse confinement reinforcement for ductility demand, and a new seismic design concept of RC bridge columns are presented.

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Approximate seismic displacement capacity of piles in marine oil terminals

  • Goel, Rakesh K.
    • Earthquakes and Structures
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    • v.1 no.1
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    • pp.129-146
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    • 2010
  • This paper proposes an approximate procedure to estimate seismic displacement capacity - defined as yield displacement times the displacement ductility - of piles in marine oil terminals. It is shown that the displacement ductility of piles is relatively insensitive to most of the pile parameters within ranges typically applicable to most piles in marine oil terminals. Based on parametric studies, lower bound values of the displacement ductility of two types of piles commonly used in marine oil terminals - reinforced-concrete and hollow-steel - with either pin connection or full-moment-connection to the deck for two seismic design levels - Level 1 or Level 2 - and for two locations of the hinging in the pile - near the deck or below the ground - are proposed. The lower bound values of the displacement ductility are determined such that the material strain limits specified in the Marine Oil Terminal Engineering and Maintenance Standard (MOTEMS) are satisfied at each design level. The simplified procedure presented in this paper is intended to be used for preliminary design of piles or as a check on the results from the detailed nonlinear static pushover analysis procedure, with material strain control, specified in the MOTEMS.

Ductility Based Seismic Design of Circular R/C Bridge Piers (원형 철근콘크리트 교각의 연성도 내진설계)

  • Choi Jin Ho;Ko Seong Hyun;Hwang Jung Kil;Lee Jea Hoon
    • Proceedings of the Korea Concrete Institute Conference
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    • 2005.11a
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    • pp.101-104
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    • 2005
  • This study is to develop detailing guidelines based on ductility demand for reinforced concrete bridge columns in areas of low to moderate seismicity. The current seismic design criteria of the Korea Design Specifications for Highway Bridge (KDSHB 2005) adopted the seismic design concept and requirements of the AASHTO specifications. In order to obtain full ductile behavior under seismic loads, i.e. when applied seismic force is larger than design flexural strength of column section, a response modification factor (R=3 or 5) is used. In moderate seismicity regions, however, adopting the full ductility design concept sometimes results in construction problems due to reinforcement congestion. The objective of this paper is to suggest a new simplified seismic design of reinforced concrete bridge columns for moderate seismicity regions.

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Ductility Demand-Based Seismic Design and Seismic Performance Evaluation of Urban Railway Bridge Pier (도시철도 고가교 및 교량 교각의 연성도 내진설계와 내진성능 평가)

  • Park, Seung-Hee;Nam, Min-Jun;Yoon, Jong-Ku;Kim, Jin-Ho
    • Proceedings of the KSR Conference
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    • 2011.10a
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    • pp.1220-1226
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    • 2011
  • The purpose of this study is to assess the seismic performance of a reinforced concrete pier using ductility demand-based seismic design method and nonlinear earthquake analysis. A computer program named MIDAS/Civil(MIDAS IT,2009) for the analysis of the reinforced concrete pier was used. The bridge pier was designed by the ductility demand-based seismic design. In addition, a seismic performance was evaluated through both capacity spectrum method and nonlinear time history method. In order to determine the seismic performance of the bridge pier, the maximum response values from the capacity spectrum method and nonlinear time history analysis were compared each other.

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Development and Practice of Performance-Based Seismic Design of High-Rise Buildings in China

  • Xiao Congzhen;Li Jianhui;Li Yinbin;Qiao Baojuan;Sun Chao;Wei Yue;Ding Jiannan
    • International Journal of High-Rise Buildings
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    • v.12 no.3
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    • pp.209-214
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    • 2023
  • Seismic performance-based design methods are widely used in the field of engineering. This paper introduces the current status of seismic performance-based design methods for high-rise buildings in China, and summarizes latest advancements in seismic performance-based design methods for high-rise buildings in China, with a focus on the design methods based on predetermined yield mode and the design methods based on member ductility requirements. Finally, the development direction of seismic performance-based design method for high-rise buildings is prospected.

Confinement Steel based on Ductility Demand for RC Bridge Columns (철근콘크리트 교각의 연성요구량에 따른 심부구속철근량)

  • 손혁수;한상엽;조재원;이재훈
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2002.09a
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    • pp.322-329
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    • 2002
  • The purpose of this study is to develop a reasonable design for transverse confinement reinforcement considering ductility and required transverse confinement reinforcement of RC bridge columns. In order to develop relationships between the curvature ductility and the displacement ductility, the analysis for total 21,600 columns using the computer program NARCC have been carried out for parametric studies. Based on the results from the parametric studies, a correlation equation between the curvature ductility and the displacement ductility was developed. In addition, an equation for calculating the required transverse confinement reinforcement based on ductility demand was developed for seismic design of RC bridge columns. The equations proposed by this study will provide more reasonable and more effective design guidelines for performance-based seismic design of RC bridge columns.

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Limited Ductility Seismic Design in Moderate Seismicity Regions (중진지역에서의 한정연성도 내진설계)

  • 김재관
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 1998.10a
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    • pp.75-84
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    • 1998
  • Korea is located in either low or moderate seismicity continental region. It is realized that design codes and underlying design concepts of high seismicity region may not be appropriate to low or moderate seismicity region. In this paper, test results on the seismic response of structures without seismic detailing are reexamined and compared with numerical analysis results. The seismic design concept based on limited ductility is proposed as an alternative seismic design approach in moderate seismicity regions.

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Seismic Design of Structures in Low Seismicity Regions

  • Lee, Dong-Guen;Cho, So-Hoon;Ko, Hyun
    • Journal of the Earthquake Engineering Society of Korea
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    • v.11 no.4
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    • pp.53-63
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    • 2007
  • Seismic design codes are developed mainly based on the observation of the behavior of structures in the high seismicity regions where structures may experience significant amount of inelastic deformations and major earthquakes may result in structural damages in a vast area. Therefore, seismic loads are reduced in current design codes for building structures using response modification factors which depend on the ductility capacity and overstrength of a structural system. However, structures in low seismicity regions, subjected to a minor earthquake, will behave almost elastically because of the larger overstrength of structures in low seismicity regions such as Korea. Structures in low seismicity regions may have longer periods since they are designed to smaller seismic loads and main target of design will be minor or moderate earthquakes occurring nearby. Ground accelerations recorded at stations near the epicenter may have somewhat different response spectra from those of distant station records. Therefore, it is necessary to verify if the seismic design methods based on high seismicity would he applicable to low seismicity regions. In this study, the adequacy of design spectra, period estimation and response modification factors are discussed for the seismic design in low seismicity regions. The response modification factors are verified based on the ductility and overstrength of building structures estimated from the farce-displacement relationship. For the same response modification factor, the ductility demand in low seismicity regions may be smaller than that of high seismicity regions because the overstrength of structures may be larger in low seismicity regions. The ductility demands in example structures designed to UBC97 for high, moderate and low seismicity regions were compared. Demands of plastic rotation in connections were much lower in low seismicity regions compared to those of high seismicity regions when the structures are designed with the same response modification factor. Therefore, in low seismicity regions, it would be not required to use connection details with large ductility capacity even for structures designed with a large response modification factor.

Seismic Design Methodology of RC Bridge Columns based on Ductility (연성도를 고려한 철근콘크리트 교각의 내진설계방법에 관한 연구)

  • 이재훈;손혁수;김준범
    • Proceedings of the Korea Concrete Institute Conference
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    • 2002.10a
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    • pp.135-140
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    • 2002
  • Bridge columns in strong earthquake area are to be designed and constructed so that enough ductility should be guaranteed. Therefore, large amount of transverse reinforcement is required to confine core concrete of the bridge column by design specifications. In moderate seismicity regions, however, adopting the full ductility design concept sometimes results in construction problems due to reinforcement congestion. For the moderate seismicity regions, a design based on required ductility and required transverse reinforcement might be a reasonable approach. Ductility demand design or performance-based design might be an appropriate approach especially for regions of moderate seismic risk. The procedure and application of this design approach are presented in this paper.

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