• Title/Summary/Keyword: 지진설계

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Seismic Responses of Wall-Slab Apartment Building Structures Built on the Soft Soil Layer Considering the Stiffnesses of a Foundation-Soil System (연약지반의 기초지반강성을 고려한 벽식구조 아파트의 지진응답)

  • 김지원;김용석
    • Journal of the Earthquake Engineering Society of Korea
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    • v.5 no.3
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    • pp.19-27
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    • 2001
  • In this seismic analyses of structures, it is well recognized that the effects of soil-structure interaction can not be ignored and seismic responses of a structure taking into account the stiffnesses of a foundation-soil system show the significant difference from those with a rigid base. However, current seismic analyses of apartment building structures were carried out with the rigid base ignoring the characteristics of the foundation and the properties of the underlying soil. In this study, seismic analyses of wall-slob type apartment buildings which have a particular structural type were carried out taking into account the soft soil layer comparing seismic response spectra of a flexible base with those of a rigid base and UBC-97. Low-rise or middle height wall-slab type apartment buildings built on the deep soft soil layer showed a rigid body motion with the reduced seismic responses due to the base isolation effect, indicating that it is considerably safe but uneconomical to utilize the design spectra of UB-97 for the seismic design of wall-slab type apartment buildings due to conservative design.

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A study on the static seimic loads for the space structures of beam string structure (장현보구조형식을 가지는 공간구조물의 정적지진하중 평가법에 관한 연구)

  • Kim, Kwang-Il;Jung, Chan-Woo;Kang, Joo-Won
    • Proceeding of KASS Symposium
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    • 2008.05a
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    • pp.127-132
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    • 2008
  • Recent years, the response characteristics of large space structures have been studied. Then, for the large space structures with large rise-span ratio, it is clarified that the anti-symmetric mode are representatively amplified. That means the static seismic load for general ramen structure is not suitable for the space structure. In this paper, we propose static seismic loads for space structures and its concept. And for the space structures of beam string structures, execute the time history analysis and quasi static analysis and compare the results of them. From the results, we can prove the validity of static seismic load for space structure.

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Structural Analysis of a Breakwater in Wave and Seismic Loads (파랑하중과 지진하중하의 방파제 구조해석)

  • Cho, Kyu-Nam
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.22 no.1
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    • pp.45-52
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    • 2009
  • In this paper, a guideline for designing breakwater in wave loads and in seismic loads is proposed. A simple model structure in breaking wave zone is examined using Morison equation in consideration with the effect of an impact load, for evaluation of the wave loads. As the impact load effect is not significant, pressure distributions according to Goda are applied for evaluation of wave loads on breakwater. Structural behavior of breakwater in wave loads can be obtained using the Goda method, as well. For seismic analysis, Ofunato and Hachinohe models, as well as an artificial seismic acceleration loads model, are adopted. Soil-structure interaction analysis is carried out to find the seismic load effect. It is found that, in certain cases, structural deformation in wave loads is in the same level as deformation that in seismic loads. Thus, it is our recommendation that these two loads are considered at the same level in breakwater design.

Directional and Orthogonal Effects of Seismic Loads on Design Member Forces (설계부재력에 대한 지진하중의 방향 및 직교성 영향)

  • Ko, Dong-Woo;Jeong, Seong-Wook;Lee, Han-Seon
    • Journal of the Earthquake Engineering Society of Korea
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    • v.9 no.3 s.43
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    • pp.51-58
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    • 2005
  • Many RC building structures of multiple uses constructed in Korea have the Irregularities of torsion and soft story at bottom stories simultaneously. Seismic design codes generally require dynamic analysis and to take into account the effect or earthquake excitations in the orthogonal direction using the approximate methods of 100/30 and SRSS for type of building structures. And ail buildings should be designed to be safe in any direction of earthquake input. But, most of designers have difficulty in considering the orthogonal and directional effect of earthquake. The objective of the study stated herein is to verily 1) the effect of the choice of the reference axes on the seismic design member forces by comparing the analytical results on member forces using the principal axes suggested by Wilson and the global axes generally adopted in design office, 2) the validity or the 100/30 and SRSS methods by comparing the member forces obtained through linear elastic time history analysis with those obtained through using response spectrum analysis and 100/30 (or SRSS) methods. Based on the observations on the analytical results, it is concluded as follows; 1) The values of member forces by principal axes can be about $15\%$ smaller than those by the global axes in the example structure. 2) Though the values of member forces given by time history analysis are generally within the peak values predicted by 100/30 and SRSS methods, many member force vectors $(P,\;M_y,\;and\;M_z)$ by lime history analysis were located outside the boundaries predicted by the approximate method such as the 100/30 method.

Analysis of Seismic Response Coefficient by Fundamental Period using Geographic Information System (GIS를 이용한 고유주기에 따른 지진응답계수 분석)

  • Seo, Eun-Su;Choi, Se-Hyu
    • Spatial Information Research
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    • v.20 no.1
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    • pp.39-45
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    • 2012
  • Response of buildings under seismic load is different according to fundamental period. It is provided in Korean Building Code(KBC2009) seismic response coefficient by fundamental period for seismic design of buildings. Recently, many researchers have studied on fundamental period and seismic response coefficient. However, studies on seismic design using Geographic Information System(GIS) are not sufficient. Therefore, this paper has analyzed on seismic response coefficient of buildings using ArcGIS. This paper can be evaluated efficiently for seismic analysis of structures. And this study will be used as basics of a reasonable seismic design using Geographic Information Systems(GIS).

Effect of the Nonlinearity of the Soft Soil on the Elastic and Inelastic Seismic Response Spectra (연약지반의 비선형성이 탄성 및 비탄성 지진응답스펙트럼에 미치는 영향)

  • Kim, Yong-Seok
    • Journal of the Earthquake Engineering Society of Korea
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    • v.9 no.4 s.44
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    • pp.11-18
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    • 2005
  • Inelastic seismic analysis is necessary for the seismic design due to the nonlinear behavior of a structure-soil system, and the importance of the performance based design considering the soil-structure interaction is recognized for the reasonable seismic design. In this study, elastic and inelastic seismic response analyses of a single degree of freedom system on the soft soil layer were peformed considering the nonlinearity of the soil for the 11 weak or moderate, and 5 strong earthquakes scaled to the nominal peak acceleration of 0.075g, 0.15g, 0.2g and 0.3g. Seismic response analyses for the structure-soil system were peformed in one step applying the earthquake motions to the bedrock In the frequency domain, using a pseudo 3-D dynamic analysis software. Study results indicate that it is necessary to consider the nonlinear soil-structure interaction effects and to perform the performance based seismic design for the various soil layers rather than to follow the routine procedures specified in the seismic design codes. Nonlinearity of the soft soil excited with the weak earthquakes also affected significantly to the elastic and inelastic responses due to the nonlinear soil amplification of the earthquake motions, and it was pronounced especially for the elastic ones.

Study on Physical Characteristics of Historical and Artificial Ground Acceleration (역사지진 및 인공지진의 물리적 특성에 관한 연구)

  • 이대형;정영수;전환석
    • Journal of the Earthquake Engineering Society of Korea
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    • v.2 no.2
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    • pp.35-44
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    • 1998
  • Because of the continual occurrence of minor and moderate earthquakes in Korean peninsula, it is generally considered that Korean is not located in a safe region against probable earthquake any more, even though being recognized as a safe country in earthquake. It is in particular noted that nowadays there has been much concern about unexpected tragedy due to probable earthquake since the disaster of 1995 kobe earthquake. Thus, the objective of this research is to develop appropriate design spectrum which could be practicably used in seismic design of important structures taking into consideration of local physical characteristics. Particularly, we have to keep in mind the lessons from 1985 Mexico earthquake which had disregarded deep research on local ground conditions, being a possible magnification phenomena of ground motions in weak soil layer. Various spectra has been described based on the analysis of historical earthquakes, and generate the artificial ground acceleration. Also, rational numbers of artificial ground acceleration is investigated by the seismic analysis for skew slab bridges.

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Effect of Evaluation Response Spectrum on the Seismic Risk of Structure (평가용 스펙트럼이 구조물의 지진리스크에 미치는 영향)

  • Kim, Min-Kyu;Choi, In-Ki
    • Journal of the Earthquake Engineering Society of Korea
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    • v.13 no.6
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    • pp.39-46
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    • 2009
  • The selection of an evaluation response spectrum can have a significant effect on the seismic fragility evaluation of a structure. A method for modifying the seismic fragility parameters that are calculated based on the design spectrum is described in this study. The modification factor is used to modify the original fragility parameters. The HCLPF (High Confidence of Low Probability of Failure) acceleration levels of the electric system using previous design spectrum and uniform hazard spectrum (UHS) were compared. Finally, seismic risk analyses were performed according to a uniform hazard spectrum. From the results, it was concluded that based on the design spectrum, seismic risk for the electric system might be underestimated.

A Preliminary Study of the Seismic Damage Estimation for Harbor Sites (항만 구역 지진피해예측 평가방안에 관한 예비 연구)

  • Choi, Seung-Ho;Kim, Han-Saem;Yoo, Seung-Hoon;Chung, Chung-Ki;Jang, In-Sung
    • Journal of the Earthquake Engineering Society of Korea
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    • v.15 no.3
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    • pp.45-55
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    • 2011
  • In this study, the state of the art and characteristics of major Korean port structures were investigated and analyzed. Damage of port structures during earthquakes, evaluation systems of seismic damage and seismic designs have also been investigated. Based on the research, a methodology of seismic damage estimation was proposed considering geotechnical information and the characteristics of the fragility of port structures.