• 제목/요약/키워드: seismic code

검색결과 672건 처리시간 0.026초

Assessment of seismic design coefficients for composite special moment frames with reinforced concrete columns and steel beams: Evaluation of code recommendations

  • Elmira Tavasoli Yousef Abadi;Mohammad T. Kazemi
    • Steel and Composite Structures
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    • 제50권6호
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    • pp.643-658
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    • 2024
  • The main aim of this study is to quantify the code seismic design coefficients of the RCS system, which consisted of reinforced concrete columns and steel beams, based on the FEMA P-695 methodology. The underlying intention is to evaluate the seismic performance of the RCS system at the system level rather than the connection level. A set of 24 archetype buildings with a various number of stories, beam span lengths, gravity load levels, and seismic load levels are selected and designed based on the prevailing code requirements. Nonlinear analytical models are developed and validated by experimental tests. The pushover and response history dynamic analyses are conducted to evaluate the required data in the performance quantification process. The results show that the design coefficients suggested by the code are acceptable. However, the level of conservatism is very high. Thus, it is possible to use a larger R-factor in the design process or make some relaxations in the design requirements related to this structural system.

원형 철근콘크리트 교각의 내진성능 영향인자에 관한 연구 (A study on Influence Parameter of Seismic Performance for Circular RC Bridge Piers)

  • 이대형;박창규;김현준;정영수
    • 한국지진공학회:학술대회논문집
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    • 한국지진공학회 2005년도 학술발표회 논문집
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    • pp.292-299
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    • 2005
  • This paper presents evaluation of seismic design code for AASHTO, Eurocode 8, NZS 3101, and ATC-32 and influence of parameter such as confinement steel ratio, axial force ratio, aspect ratio and longitudinal steel ratio. These seismic design code prescribe confinement steel ratio for appropriate seismic performance which is considered various design parameter. But there is doubt that these parameters are considered rationally in seismic design code. The object of this research is rational evaluation of seismic performance by analysis of existing related experimental research. According to this research, most influence parameter of seismic performance is axial force ratio.

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호주의 비보강 조적조에 대한 내진기준 (Australian Seismic Code for Unreinforced Masonry)

  • 이한선;유은진
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2001년도 봄 학술발표회 논문집
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    • pp.815-820
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    • 2001
  • This paper provides an overview of the unreinforced masonry in Australian Standard, especially places the focus on a seismic code. Australia, like Korea, is a country of lower seismicity, and strengthens the code of unreinforced masonry since Newcastle earthquake of magnitude 5.6 in 1989. It is useful in establishing Korean code for unreinforced masonry to compare Australian Standard to Korean.

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A review of seismic design recommendations in Jordan

  • Saffarini, Hassan S.
    • Structural Engineering and Mechanics
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    • 제9권3호
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    • pp.257-268
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    • 2000
  • The seismic design recommendations of the Jordan Code for Loads and Forces (JC) are evaluated, based on comparisons with analytical studies and the Uniform Building Code. It was established that the overall safety ensured by the implementation of these recommendations is not consistent with the established seismic risk in Jordan and the intended objectives of the code. A new zoning map is proposed with effective peak ground acceleration values. The different period formulae of the code were studied and were found to grossly underestimate the fundamental period when compared with analytically derived values or other codes' formulae. Other factors including the dynamic, soil, importance and behavior factors are discussed. It was determined that the JC's lateral load distribution formulae clearly lead to smaller internal forces than both dynamic analysis and UBC loads, even when those loads are normalized to give the same base shear. The main reason for this is attributed to the limited allowance for a backlash force in the JC.

현행 도로교시방서의 지반계수에 대한 공학적 영향평가 (Engineering Impact Assessment of the Site Coefficients In the Current Highway Bridge Code of Korea)

  • 조양희
    • 한국지진공학회:학술대회논문집
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    • 한국지진공학회 1998년도 춘계 학술발표회 논문집 Proceedings of EESK Conference-Spring 1998
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    • pp.89-97
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    • 1998
  • This study is intended to investigate the seismic responses of bridge structures considering site effects. The site effects in the seismic analysis of bridge structures were classified into two parts. At first, the seismic responses of the structures on each "soil profile types" of the code were evaluated in accordance with code-specified method and compared with results of time-history analysis method. And next, as a second stage of the study, the responses of the two different soil with considerably different soil properties, even though they are classified to the same "soil profile types" of the code, were evaluated and compared each other. The first part of study is purposed to evaluate the applicability of code-specified method, while the other part is purposed to find the variance of the seismic responses from the different soil sites in the same soil profile types of the code. For the analysis, two major methods of the code, single-mode spectral anaysis and multi-mode spectral analysis, were used and the time-history analysis method which is expected to give more accurate responses was also used for the comparison purposes. For the time-history analysis, time-domain analysis technique of the lumped-mass model with frequency-independent soil springs and dampers was adopted and artificially generated spectra of the code was used as input motion. As the results of the study, the code specified methods for the seismic responses considering the site effects were verified to give the results in conservative side for the most of the cases. However, for the structures on the site with considerable flexibility, the responses of the bridge girders or deckplates by the code methods both in section forces and horizontal movement responses, may have much smaller values than the actual responses. Therefore, more detailed analysis considering the flexibility of the base soil may be required to have more reasonable results in girder responses.in girder responses.

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현행 내진설계 규준에서 요구되는 수평강도의 평가 방법 (Method of Evaluation of the Strength Required in Current Seismic Design Code)

  • 한상환
    • 한국지진공학회:학술대회논문집
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    • 한국지진공학회 1997년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Fall 1997
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    • pp.193-200
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    • 1997
  • Current seismic design code is based of the assumption that the designed structures would be behaved inelastically during a severe earthquake ground motion. For this reason, seismic design forces calculated by seismic codes are much lower than the forces generated by design earthquakes which makes structures responding elastically. Present procedures for calculating seismic design forces are based on the use of elastic spectra reduced by a strength reduction factors known as "response modificaion factor". Because these factors were determined empirically, it is difficult to know how much inelastic behaviors of the structures exhibit. In this study, base shear forces required to maintain target ductility ratio were first calculated from nonlinear dynamic analysis on the single degree of freedom system. And then, base shear foeces specified in seismic design code compare with above results. If the strength(base shear) required strength should be filled by overstrength and/or redundancy. Therefore, overstrength of moment resisting frame structure will be estimated from the results of static nonlinear analysis(push-over analysis).analysis).

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The effect of different earthquake ground motion levels on the performance of steel structures in settlements with different seismic hazards

  • Isik, Ercan;Karasin, ibrahim Baran;Karasin, Abdulhalim
    • Structural Engineering and Mechanics
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    • 제84권1호
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    • pp.85-100
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    • 2022
  • The updated Turkish Building Earthquake Code has been significantly renovated and expanded compared to previous seismic design codes. The use of earthquake ground motion levels with different probabilities of exceedance is one of the major advances in structural mechanics with the current code. This study aims to investigate the earthquake performance of steel structure in settlements with different seismic hazards for various earthquake ground motion levels. It is focused on earthquake and structural parameters for four different ground motion levels with different probabilities of exceedance calculated according to the location of the structure by the updated Turkish Hazard Map. For this purpose, each of the seven different geographical regions of Turkey which has the same seismic zone in the previous earthquake hazard map has been considered. Earthquake parameters, horizontal design elastic spectra obtained and comparisons were made for all different ground motion levels for the seven different locations, respectively. Structural analyzes for a sample steel structure were carried out using pushover analysis by using the obtained design spectra. It has been determined that the different ground motion levels significantly affect the expected target displacements of the structure for performance criteria. It is noted that the different locations of the same earthquake zone in the previous code with the same earthquake-building parameters show significant variations due to the micro zoning properties of the updated seismic design code. In addition, the main innovations of the updated code were discussed.

지진하중을 받는 원자력 내진등급 2A 글로브 밸브의 구조 건전성 평가 (Structural Integrity Evaluation of Nuclear Seismic Category IIA 2" Globe Valve for Seismic Loads)

  • 정철섭
    • 한국산학기술학회논문지
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    • 제9권6호
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    • pp.1500-1505
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    • 2008
  • 본 논문은 원자력 내진등급 IIA 글로브 밸브의 지진하중에 대한 구조 건전성을 평가하였다. 밸브 구조물을 3차원 모델링하여 유한요소법을 사용하여 모달 해석 및 등가 정적 응력해석을 수행하였다. 모달 해석 결과 밸브 구조물은 충분히 강건하여 등가 정적해석이 가능하였고 해석에서 구한 응력들을 조합하여 원자력 규격집에서 제시한 허용응력과 비교하여 밸브의 구조 건전성을 판단하였다. 모든 지진하중에 대한 밸의 구조물에서의 응력은 허용값 보다 작게 분포하므로 구조적 건전성을 유지한다고 평가할 수 있다.

Effect of design spectral shape on inelastic response of RC frames subjected to spectrum matched ground motions

  • Ucar, Taner;Merter, Onur
    • Structural Engineering and Mechanics
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    • 제69권3호
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    • pp.293-306
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    • 2019
  • In current seismic design codes, various elastic design acceleration spectra are defined considering different seismological and soil characteristics and are widely used tool for calculation of seismic loads acting on structures. Response spectrum analyses directly use the elastic design acceleration spectra whereas time history analyses use acceleration records of earthquakes whose acceleration spectra fit the design spectra of seismic codes. Due to the fact that obtaining coherent structural response quantities with the seismic design code considerations is a desired circumstance in dynamic analyses, the response spectra of earthquake records used in time history analyses had better fit to the design acceleration spectra of seismic codes. This paper evaluates structural response distributions of multi-story reinforced concrete frames obtained from nonlinear time history analyses which are performed by using the scaled earthquake records compatible with various elastic design spectra. Time domain scaling procedure is used while processing the response spectrum of real accelerograms to fit the design acceleration spectra. The elastic acceleration design spectra of Turkish Seismic Design Code 2007, Uniform Building Code 1997 and Eurocode 8 are considered as target spectra in the scaling procedure. Soil classes in different seismic codes are appropriately matched up with each other according to $V_{S30}$ values. The maximum roof displacements and the total base shears of considered frame structures are determined from nonlinear time history analyses using the scaled earthquake records and the results are presented by graphs and tables. Coherent structural response quantities reflecting the influence of elastic design spectra of various seismic codes are obtained.

건축 비구조재의 내진설계요소 및 내진설계하중에 관한 고찰 (Investigation on Seismic Design Component and Load for Nonstructural Element)

  • 최인섭;이주희;손정훈;김준희
    • 대한건축학회논문집:구조계
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    • 제35권5호
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    • pp.117-124
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    • 2019
  • Nonstructural elements are installed according to the function of a building, and refer to the elements other than a structural system that resists external loads. Although the nonstructural elements had the largest part of seismic loss of buildings, seismic design of buildings mainly focuses on structural system and the seismic design of nonstructural elements are rarely conducted. In this study, the seismic design provisions of nonstructural elements presented in Uniform Building Code (UBC) and International Building Code (IBC) were investigated in order to analyze the seismic design considerations of nonstructural elements presented in Korean Building Code (KBC). The results showed that the equivalent static load applied to seismic design of nonstructural elements was revised to take into consideration a total of five items such as effective ground acceleration, vertical amplification factor, response amplification factor, response modification factor, importance factor.