• Title/Summary/Keyword: seismic hazard/mitigation

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Parametric Study on Seismic Performance of Internally Confined Hollow CFT Column (내부 구속 중공 CFT 교각의 내진성능에 대한 매개변수 연구)

  • Kim, Hyun-Jong;Yeom, Eung-Jun;Han, Taek-Hee;Kang, Young-Jong
    • 한국방재학회:학술대회논문집
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    • 2007.02a
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    • pp.144-147
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    • 2007
  • Internally Confined Hollow-Concrete Filled Tube(ICH-CFT) column which has two tubes on both side of concrete, inner tube and outer tube perform great seismic abilities, ductility and absorption of energy, by the tubes and the hollow part. So this study does qualitative analysis about seismic capacities depending on parameters - diameter of column, hollow ratio, thickness of tubes - by moment-curvature analysis.

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Peak Factors for Bridges Subjected to Asynchronous Multiple Earthquake Support Excitations

  • Yoon, Chong-Yul;Park, Joon-Seok
    • Journal of the Korean Society of Hazard Mitigation
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    • v.11 no.1
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    • pp.7-13
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    • 2011
  • Accurate response analysis of long span bridges subjected to seismic excitation is important for earthquake hazard mitigation. In this paper, the performance of a typical four span continuous reinforced concrete bridge model subjected to asynchronous multiple seismic excitations at the supports is investigated in both the time and frequency domains and the results are compared with that from a relevant uniform support excitations. In the time domain analysis, a linear modal superposition approach is used to compute the peak response values. In the frequency domain analysis, linear random vibration theory is used to determine the root mean square response values where the cross correlation effects between the modal and the support excitations on the seismic response of the bridge model are included. From the two sets of results, a practical range of peak factors which are defined to be the ratio of peak and the root mean square responses are suggested for displacements and forces in members. With reliable practical values of peak factors, the frequency domain analysis is preferred for the performance based design of bridges because of the computational advantage and the generality of the results as the time domain analysis only yields results for the specific excitation input.

Earthquake Resistant Design Methods on the Slopes (지진을 고려한 비탈면 설계 방안)

  • Kim, Ju-Hyong;Lee, Yong-Su;Cho, Sam-Deok
    • Journal of the Korean Society of Hazard Mitigation
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    • v.5 no.1 s.16
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    • pp.23-32
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    • 2005
  • A significant development has been made on earthquake resistant designs on many structures since the Korean government has begun modern earthquake hazard reduction programs after recognizing potential disastrous consequences of seismic events following the Kobe earthquake in 1995. However, some structures such as slope structures still haven't get ready for their own seismic design guidelines in Korea. Therefore, only a few organizations of Korea adopt seismic design for slopes relying on designers' judgments at present. This paper introduces domestic and foreign research activities on seismic slope stability and an idea of Korean earthquake resistant design method for slopes including alternatives of earthquake resistant design application according to designers' judgment considering construction budget, importance, restoration and so on. Afterwards, seismic data accumulation on slope stability of Korea is necessary to induce a more definite Korean earthquake resistant design method.

Probabilistic earthquake risk consideration of existing precast industrial buildings through loss curves

  • Ali Yesilyurt;Seyhan O. Akcan;Oguzhan Cetindemir;A. Can Zulfikar
    • Geomechanics and Engineering
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    • v.37 no.6
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    • pp.565-576
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    • 2024
  • In this study, the earthquake risk assessment of single-story RC precast buildings in Turkey was carried out using loss curves. In this regard, Kocaeli, a seismically active city in the Marmara region, and this building class, which is preferred intensively, were considered. Quality and period parameters were defined based on structural and geometric properties. Depending on these parameters, nine main sub-classes were defined to represent the building stock in the region. First, considering the mean fragility curves and four different central damage ratio models, vulnerability curves for each sub-class were computed as a function of spectral acceleration. Then, probabilistic seismic hazard analyses were performed for stiff and soft soil conditions for different earthquake probabilities of exceedance in 50 years. In the last step, 90 loss curves were derived based on vulnerability and hazard results. Within the scope of the study, the comparative parametric evaluations for three different earthquake intensity levels showed that the structural damage ratio values for nine sub-classes changed significantly. In addition, the quality parameter was found to be more effective on a structure's damage state than the period parameter. It is evident that since loss curves allow direct loss ratio calculation for any hazard level without needing seismic hazard and damage analysis, they are considered essential tools in rapid earthquake risk estimation and mitigation initiatives.

Dynamic Behavior of Curved Bridges under Seismic Loading (지진하중을 받는 곡선교량의 동적거동)

  • Park, Nam-Hoi;Yoon, Ki-Yong;Kang, Young-Jong
    • Journal of the Korean Society of Hazard Mitigation
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    • v.5 no.3 s.18
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    • pp.11-21
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    • 2005
  • This study is performed to understand complex behavior and to investigate the rational analysis methods for seismic design of the curved bridges. To analyze the curved bridges for the seismic loadings, it is used that the finite element analysis program has the 7-dof curved beam and straight beam element. The free vibration characteristics of the curved bridges are compared with the straight bridges that have span length same as the average arc length of inside and outside girder of those. For the same case, the dynamic behavior is compared under seismic loadings. It is found that regular bridges classified by AASHTO are analyzed as if those were straight. To investigate the dynamic behavior of general curved bridges under seismic loading, the seismic loading directions and the subtended angle of curved bridges are varied.

Non-Prismatic Beam Element for Nonlinear Seismic Analysis of Steel Moment Frames II: Verification of Model (강재 모멘트 골조의 비선형 지진 해석을 위한 부등단면 보 요소 II: 모델의 검증)

  • Hwang, Byoung-Kuk;Cheon, Chung-Ha;Kim, Kee-Dong;Ko, Man-Gi
    • Journal of the Korean Society of Hazard Mitigation
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    • v.7 no.5
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    • pp.37-46
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    • 2007
  • This is the second of two companion papers that describe non-prismatic beam element for nonlinear seismic analysis of steel moment frames. Described in a companion paper is the formulation of a non-prismatic beam element to model the elastic and inelastic behavior of steel beams, which have reduced beam sections(RBS). This study describes the determination of yield surfaces, stiffness parameters, and hardening (or softening) rule parameters for RBS beam element. Analytical results of the RBS beam element show good correlation with test data and Finite Element Method(FEM) results.

Seismic Performance of Internally Confined Hollow RC Column with Corrugated Steel Tube (파형강관 내부 구속 중공 철근 콘크리트 기둥의 내진 성능)

  • Han, Taek-Hee;Kim, Jong-Min;Kang, Jun-Suk;Kang, Young-Jong
    • Journal of the Korean Society of Hazard Mitigation
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    • v.8 no.2
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    • pp.31-38
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    • 2008
  • A column test was performed far a new-type column with a quasi static test. An internally confined hollow reinforced concrete column with a corrugated steel tube (ICH RC-CT column) was tested to evaluate its seismic performance. And also, a general solid RC column was tested fur the comparison. The test was performed as planned drift levels. The lateral displacements and the lateral loads of column specimens were measured during tests. From the test results, the ICH RC-CT column showed smaller energy absorbing capacity than a solid RC column but showed the almost equal energy ductility and equivalent viscous damping ratio to those of the solid RC column.

Selection of Presentable Seismic Ground Motion Scenario through Deaggregation (Deaggregation을 통한 대표지진시나리오 선정)

  • Kwak, Dong-Yeop;Yun, Se-Ung;Park, Du-Hee
    • 한국방재학회:학술대회논문집
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    • 2008.02a
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    • pp.261-263
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    • 2008
  • Determining the most likelihood earthquake scenario in one region is very important for performing an earthquake-resistant design. The most likelihood earthquake scenario can be selected by performing deaggregation, who classifies earthquakes that occur ground motion exceeding a specific acceleration as each distance and each earthquake magnitude. If earthquakes are classified, the most likelihood earthquake scenario can be selected. Earthquake hazard analysis method that have to be performed before deaggregation follows the method that Ministry of Construction & Transportation presented. As a result of performing deaggregation at longitude 127.35 and latitude 34.7, presentable seismic ground motion scenarios can be selected at each recurrence period.

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