• Title/Summary/Keyword: 내진설계기준

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The Effect of the Shear Wave Velocity of a Seismic Control Point on Site Response Analysis (기반암 전단파속도의 부지응답특성 영향평가)

  • Lee, Jin-Sun
    • Journal of the Earthquake Engineering Society of Korea
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    • v.13 no.1
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    • pp.1-8
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    • 2009
  • In order to evaluate the effect of shear wave velocity of a seismic control point on site response analysis, one-dimensional equivalent linear site response analysis were performed on the model soil profile based on the results of a detailed site investigation of sedimentary layers at Incheon and Busan. The results of the analysis show that an increase of shear wave velocity on the seismic control point (base rock) results in an increase of acceleration in the soil layers. This was mainly due to an unclear definition of the seismic control point. For this reason, the Korean Seismic Design Standard requires a specific definition of the seismic control point, including spatial conditions and soil properties, similar to the MCE (Maximum Considered Earthquake) in FEMA 369.

A Study on Performance-based Seismic Design Method of Fire Extinguishing Pipe System (소화설비 배관의 성능위주 내진설계 방법에 관한 연구)

  • Lee, Jae-Ou;Kim, Hong-Kyung;Cho, Soon-Bong
    • Fire Science and Engineering
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    • v.31 no.4
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    • pp.86-94
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    • 2017
  • In the present study, a Cook Book method and a Static System Analysis method were compared with each other on the basis of a seismic design criteria of fire-fighting facilities and analyzed. The Cook Book method is analyzed by dividing a pipeline in each same section. In this method, a stress analysis is not possible except for the section analyzed in such a way that a brace is designed according to the weight of pipe, water and pipe fitting. To the contrary, in case of the Static System Analysis method, the stress analysis for the whole pipeline can be performed because the whole pipeline is regarded as a single structure. For the fatal stress values locally generated, it is necessary to actively perform a pipeline analysis by installing a device capable of locally relieving the stress of the pipeline. In Korea, only the Cook Book method is provided as the seismic design criteria of fire-fighting facilities, which causes many problems with diversification of seismic design. Thus, it is necessary to apply the seismic design method of the pipeline by using various kinds of engineered Static System Analysis methods.

Quasi-Static Tests for Seismic Performance of Circular RC Bridge Piers (단일주 원형 철근콘크리트 교각의 내진거동에 관한 준정적 실험)

  • 정영수;이강균;한기훈;박종협
    • Journal of the Earthquake Engineering Society of Korea
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    • v.3 no.2
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    • pp.55-66
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    • 1999
  • Eight RC bridge plers have been made on a 1/3.4 scale model and have been tested in a quasi-static cyclic load so as to investigate their seismic performance. The ultimate objective of this experimental study is to investigate the hysteretic behavior of reinforced concrete plers, which have been widely used for urban transportation facilities in Korea. Improtant test parameters are hoop ratio, axial load, load pattern, and etc. And noninear behaviors of test columns have been evaluated through their yield and ultimate strength, energy dissipation, ductility and load-deflection characteristics under quasi-static cyclic loads. From the quasi-static tests on 8 bridge piers, it is concluded that energy dissipation, ultimate strength and curvature for a given displacement factor ${\mu}={\Delta}/{\Delta}_y$ are higher for the seismically designed columns than for the nonseismically designed columns.

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Compressive Behavior of H-section Brace Strengthened by Non-welded Cold-Formed Element (무용접 냉간성형 조립재로 보강한 H형강 가새의 압축거동)

  • Kim, Sun Hee;Kim, Do Bum;Choi, Sung Mo
    • Journal of Korean Society of Steel Construction
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    • v.27 no.2
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    • pp.169-180
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    • 2015
  • Recently, Seismic performance of the building built in the past is required to review, because the code for seismic design have been reinforced. In 2009, if the revised latest criteria of seismic design is applied, the majority the steel structure of the low-rise concentrically braced system is short of the seismic performance. Also, when the steel braces are subject to compressive load, which causes unstable behavior of the structure. In order to verify the compressive behavior of the reinforced braces, structural performance test was conducted with variables of slenderness ratio and the amount of reinforcement. Therefore, this study suggests restraining the bending buckling of slender H-shaped braces to resist compressive force. In order to verify the compressive behavior of the reinforced braces, structural performance test was conducted with variables of slenderness ratio and the amount of reinforcement.

Study on the Site Classification and Site Coefficients for the Seismic Design Regulations of KBC (KBC 내진설계기준을 위한 지반분류와 지반계수에 대한 연구)

  • Kim, Yong-Seok
    • Journal of the Earthquake Engineering Society of Korea
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    • v.11 no.1 s.53
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    • pp.59-65
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    • 2007
  • Site classification of IBC and KBC is based on the ft-kips unit system and is not friendly for the linear interpolation of the site coefficients due to the implicit relationship between a site class and site coefficients, defining a site class by the range of the soil properties, not by a single soil property. Also, the site class definition of KBC has too wide range of soil properties for each soil class. making the structural engineers difficult to estimate the site coefficients for the diverse soil layers. In this study, a new site classification in SI unit system was proposed for the seismic design codes of KBC etc., and the comparison of the site coefficients of $F_{a}\;and\;F_{v}$ was also performed to investigate the possibility of the linear interpolation of the site coefficients with the proposed new site classification. According to the study results, it was more reasonable for the linear interpolation of the site coefficients to utilize the proposed new site classification considered the Sl unit system and the soil characteristics of the 30m soil layer beneath the shallow embedded foundation, and the linear interpolation of the acceleration coefficients for the design spectrum can be performed more reasonably defining the site coefficients for the representative shear wave velocities of each site class. With the study results, a new site classification, and the linear interpolation permitted acceleration coefficients fer the design spectrum were proposed for the modification of the seismic design regulations of KBC.

중약진 지역에서 지진격리장치를 사용한 교량의 내진 보강

  • 김용길;권기준
    • Proceedings of the Korean Institute of Industrial Safety Conference
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    • 2000.06a
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    • pp.223-228
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    • 2000
  • 지진격리교량은 강진지역의 지반운동과 구조물의 거동에 근거한 내진설계 개념을 바탕으로 설계되었다. 그러나 지반운동의 특성과 구조물의 거동에 있어서 한반도와 같은 중약진 지역과 지각변동운동이 활발한 강진지역은 큰 차이를 보이고 있다. 따라서 중약진 지역의 내진설계에서는 지반운동의 특성이 반영되어야 할 필요가 있으며, 특히, 지진격리교량의 경우에는 교각의 연성 등 중약진 지역의 구조물의 거동특성이 반영되어야 한다. (중략)

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Pseudo Dynamic Test for the Seismic Performance Enhancement of Circular RC Bridge Piers Retrofitted with Fibers (섬유보강 원형 철근콘크리트 교각의 내진성능 향상에 관한 유사동적 실험)

  • 정영수;박종협;박희상;조창백
    • Journal of the Korea Concrete Institute
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    • v.14 no.2
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    • pp.180-189
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    • 2002
  • The objective of this experimental research is to assess the seismic performance of circular RC bridge pier specimens retrofitted with fibers which were designed as a prototype of Hagal bridge in the city of Suwon, Korea. Pseudo dynamic test has been done for four(4) test specimens which were nonseismically or seismically designed by the related provisions of the Korea roadway bridge design specification, and four nonseisemic test specimens retrofitted with fibers in the plastic hinge region. Glass and carbon fiber sheets were used for the seismic capacity enhancement of circular test specimens. Important test parameters were confinement steel ratio, load pattern, and retrofitting. The seismic behavior has been analyzed through the displacement ductility, energy analysis, and capacity spectrum. Approximate 7.7 ∼8.7 displacement ductility was observed for nonseismic test specimens retrofitted with fibers subjected to Korea Highway Cooperation artificial earthquake motions. It is concluded that these retrofitted test specimens could have sufficient seismic capacity in the region of moderate seismic zone.

Strengthening of an Existing Bridge for Achievement of Seismic Performance (내진성능 확보를 위한 기존교량의 보강)

  • Kook, Seung-Kyu
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.22 no.2
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    • pp.181-187
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    • 2009
  • After introduction of the earthquake resistant design code, it is required to achieve seismic performance of existing bridges as well as earthquake resistant design of new bridges. The achievement of seismic performance for existing bridges should satisfy the no collapse requirement based on the basic concept of earthquake resistant design, therefore, various methods with different strengthening scale should be suggested according to bridge types and importance categories. At present for typical bridges, most studied and applied strengthening methods are bearing change, pier strengthening and shear key installation for improvement of seismic performance. In this study a typical existing bridge, for which earthquake resistant design is not considered, is selected as an analysis bridge. Design changes are carried out to satisfy the no collapse requirement by way of the ductile failure mechanism and seismic performances are checked. It is shown that the seismic performance of existing bridges can be achieved by way of redesign of bridge system, e.g. determination of pier design section for substructure and change of bearing function for connections between super/sub-structure.

No Collapse Design for Typical Bridges (일반교량의 붕괴방지설계)

  • Kook, Seung-Kyu
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.27 no.3
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    • pp.163-172
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    • 2014
  • The purpose of earthquake resistant design for typical bridges is the No Collapse Design and the Earthquake Resistant Design Part of Roadway Bridge Design Code provides a design process to construct the Ductile Failure Mechanism for the bridge structure. However, if it is not practical to provide the Ductile Failure Mechanism due to structure types or site conditions, the Brittle Failure Mechanism is an alternative way to get the No Collapse Design. As well as the existing design process constructing the Ductile Failure Mechanism, the Earthquake Resistant Design Part provides a ductility-based design process as an appendix, which is prepared for bridges with reinforced concrete piers. According to the new design process, designer determines a required response modification factor for substructure and transverse reinforcement for confinement therefrom. In this study, a typical bridge with steel bearing connections and reinforced concrete piers is selected for which the existing as well as the ductility-based design processes are applied and different results from the two design processes are identified. Based on the results, an earthquake resistant design procedure is proposed in which designers should consider the two design processes.