• Title/Summary/Keyword: seismic hazard/mitigation

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A Study on the Presumption for Attenuation Relation by MT. O-dae earthquake data in Korea (오대산 지진자료에 의한 거리감쇠식 추정에 관한 연구)

  • Kwon, Ki-Hyuk;Hwang, Wan-Seon;Yu, Hye-Ran
    • 한국방재학회:학술대회논문집
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    • 2008.02a
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    • pp.33-36
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    • 2008
  • In Korean Building Code 2005(KBC-2005), the Seismic Zone Factor is regulated by separating the seismic zone into two part. This seismic zone factor is not matched to regional seismic characteristics of our country because the factor is based on International Building Code 2000 (IBC-2000) of USA. This study inquiry for having a sufficient grasp of the seismic characteristics of south Korea region and appling for the seismic cope plan. We have collected and analyzed earthquake record happened in domestic region. There are two kinds of earthquake record. One is Historical earthquake data, another is Instrumental earthquake data. I used Instrumental earthquake record data which reliance is higher than historical earthquake data for proposing attenuation formulas by analyzing a correlation the epicenter and the distance.

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Seismic Performance of Rib Plate H Beam to Column Connections (리브로 보강된 기둥-보 접합부의 내진성능 평가)

  • Kim, Sung-Yong;Shin, Chang-Hoon
    • Journal of the Korean Society of Hazard Mitigation
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    • v.6 no.1 s.20
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    • pp.9-16
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    • 2006
  • The moment resisting frame has been well-known as it had very excellent seismic performance, and it has been widely used and constructed in the design of a lot of buildings. However, the moment resisting frame system did not exert the seismic performance during the earthquake in Northridge and Kobe sufficiently, and it produced the crack or brittle fracture on the joint. this study was to ]m tests with the full-scale test subject as parameters of existence of H-beam web high tensile bolt shearing joint and reinforcement of H-flange rib. This researcher was to anticipate the decrease of number of high tensile bolts and the improvement of workability through the double shear joint by the experiment, and improve the seismic performance through the reinforcement of rib plate. In addition, this study was to prevent the brittle fracture by the stress concentration through the non scallop.

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

  • Yeom, Eung-Jun;Kim, Hyun-Jong;Han, Taek-Hee;Kang, Young-Jong
    • Journal of the Korean Society of Hazard Mitigation
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    • v.8 no.1
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    • pp.15-21
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    • 2008
  • The internally confined hollow-concrete filled tube (ICH-CFT) column has two tubes on the both sides (hollow part and outer part) of the concrete. The inner tube and the outer tube perform great seismic abilities, ductility and absorption of energy due to the steel tubes and the hollow part. So, the study of this column type for the practical use is needed. In this study, the qualitative analysis about seismic capacities depending on parameters is performed for the practical design of the ICH-CFT column. The parameters are diameter of column, hollow ratio and thickness of tubes with the same resistance of the moment. Also, the economical evaluation of ductility and comparison with CFT column make this study to be of practical use. Especially, a change of seismic performance depends on the hollow ratio and the thickness of the outer tube, and the economical hollow ratios according to the thickness of the outer tube in the ICH-CFT column are suggested.

Rapid Earthquake Location for Earthquake Early Warning (지진조기경보를 위한 신속 진앙위치 결정)

  • Kim, Kwang-Hee;Rydelek, Paul A.;Suk, Bong-Chool
    • Journal of the Korean Society of Hazard Mitigation
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    • v.8 no.6
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    • pp.73-79
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    • 2008
  • Economic growth, industrialization and urbanization have made society more vulnerable than ever to seismic hazard in Korea. Although Korea has not experienced severe damage due to earthquakes during the last few decades, there is little doubt of the potential for large earthquakes in Korea as documented in the historical literature. As we see no immediate promise of short-term earthquake prediction with current science and technology, earthquake early warning systems attract more and more attention as a practical measure to mitigate damage from earthquakes. Earthquake early warning systems provide a few seconds to tens of seconds of warning time before the onset of strong ground shaking. To achieve rapid earthquake location, we propose to take full advantage of information from existing seismic networks; by using P wave arrival times at two nearest stations from the earthquake hypocenter and also information that P waves have not yet arrived at other stations. Ten earthquakes in the Korean peninsula and its vicinity are selected for the feasibility study. We observed that location results are not reliable when earthquakes occur outside of the seismic network. Earthquakes inside the seismic network, however, can be located very rapidly for the purpose of earthquake early warning. Seoul metropolitan area may secure $10{\sim}50$ seconds of warning time before any strong shaking starts for certain events. Carefully orchestrated actions during the given warning time should be able to reduce hazard and mitigate damages due to potentially disastrous earthquakes.

Non-Prismatic Beam Element for Nonlinear Seismic Analysis of Steel Moment Frames I: Element Formulation (강재 모멘트 골조의 비선형 지진 해석을 위한 부등단면 보 요소 I: 요소개발)

  • Hwang, Byoung-Kuk;Jeon, Seong-Min;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.27-35
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    • 2007
  • This study presents a non -prismatic beam element for modeling the elastic and inelastic behavior of the steel beam, which has the post-Northridge connections in steel moment frames that are subjected to earthquake ground motions. The elastic stiffness matrix for non-prismatic members with reduced beam section (RES) connection is in the closed-form. The plasticity model is of a discrete type and is composed of a series of nonlinear hinges connected by rigid links. The hardening rules can model the inelastic behavior for monotonic and random cyclic loading, and the effects of local buckling. Verification and calibration of the model are presented in a companion paper.

Determination of Optimal Support for Cable-stayed Bridge Designs (사장교의 설계를 위한 최적 지지조건 결정)

  • An, Zu-Og;Yoon, Young-Man
    • Journal of the Korean Society of Hazard Mitigation
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    • v.3 no.4 s.11
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    • pp.103-109
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    • 2003
  • A numerical analysis of cable-stayed bridge is conducted to determine optimum longitudinal modulus of elasticity which represents the boundary condition between the tower and main girder. The effect of longitudinal modulus of elasticity is investigated for different loading condition (live load, wind load, seismic load), respectively. There are significant changes in the member forces as variations of longitudinal modulus of elasticity, such as, $k_h$=e=100tonf/m/bearing (live load), $k_h$=e=1000tonf/m/bearing (seismic load), However, the wind loads do not affect member forces. The optimum longitudinal modulus of elasticity is determined from considering minimum member forces in the numerical analysis results.

Development of the Damping Coefficients for Weak and Moderate Earthquake Ground Motions

  • Kim, Myeong-Han
    • Journal of the Korean Society of Hazard Mitigation
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    • v.8 no.5
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    • pp.1-6
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    • 2008
  • Most of seismic design code provisions provide the design response spectra for defining design earthquake ground motions. The design spectra in the code provisions generally come under the 5% of critical damping value, which corresponds to the responses of common structure under the design earthquake. Energy dissipation devices and seismic isolation systems became more popular and the design response spectra at higher damping levels are required. Damping coefficients can be effectively used in conversion of 5%-damped design spectra into other damping levels. These coefficients in the current seismic design code provisions are based on the strong ground motion records. Since the weak and moderate earthquake data have different characteristics from those of strong earthquake data, the application of these coefficients should be investigated in the weak and moderate earthquakes zones. In this study, damping coefficients based on the weak and moderate ground motions were developed and compared to those of current seismic design code provisions.