• 제목/요약/키워드: Seismic characteristics

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중수로형 핵연료 저장대의 내진해석 방법 (Seismic Analysis of Spent Fuel Storage Structures for PHWR Plant)

  • 신태명
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2003년도 추계학술대회논문집
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    • pp.338-344
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    • 2003
  • The seismic analysis method of spent fuel storage structures for PHWR plant is introduced in comparison with the method for PWR plant. Investigating the structural characteristics of the storage structures, the former is vertically stacked fuel storage trays, while the latter is welded honeycomb type structure. However, as both structures are submerged and free standing, the analysis methods to anticipate the seismic response of both structures are complicated. For the better estimation of actual seismic response, how to model the dynamic properties and the structural behaviour is the key issue. In this paper, the overall procedures of the seismic modelling and stability check for seismic sliding and overturning of the two different storage structures are discussed in the viewpoint of analysis reliability

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ISSUES IN PROBABILISTIC SEISMIC HAZARD ANALYSIS FOR NUCLEAR FACILITIES IN THE US

  • Mcguire, Robin K.
    • Nuclear Engineering and Technology
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    • 제41권10호
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    • pp.1235-1242
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    • 2009
  • Probabilistic seismic hazard analysis (PSHA) is routinely conducted in the US for nuclear plants, for the determination of appropriate seismic design levels. These analyses incorporate uncertainties in earthquake characteristics in stable continental regions (where direct observations of large earthquakes are rare), in estimates of rock motions, in site effects on strong shaking, and in the damage potential of seismic shaking for engineered facilities. Performance goals related to the inelastic deformation of individual components, and related to overall seismic core damage frequency, are used to determine design levels. PSHA has the ability to quantify and document the important uncertainties that affect seismic design levels, and future work can be guided toward reducing those uncertainties.

적층고무베어링을 사용한 면진구조물의 지진해석방법 (Seismic Analysis Method for the Seismically Isolated Structures Using LRBs)

  • Koo, Gyeong-Hoi;Lee, Jae-Han
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2001년도 가을 학술발표회 논문집
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    • pp.553-560
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    • 2001
  • To substantiate the application of LRB(Laminated Rubber Bearing) to the seismic isolation system, it is necessary to develop a seismic analysis method considering the non-linear behavior of LRBs, which may significantly affect the seismic responses. In this paper, seismic analyses and shaking table tests are carried out for a seismically isolated structure using four LRBs. The parameter equations of seismic isolation frequency are obtained from the shaking table tests and the quasi-static tests of LRB itself to investigate the effects of the LRB characteristics in the prediction of maximum peak acceleration responses by analysis. From the comparison of the maximum peak acceleration responses obtained from numerical analyses and experiments, it is verified that the horizontal stiffness variations of LRB should be carefully considered in seismic analysis to obtain more accurate results.

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면진주파수가 원통형탱크의 구조응답에 미치는 영향 (Effects of Seismic Isolated Frequency in Structural Responses of Cylindrical Tanks)

  • 구경회;이재한;유봉
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 1995년도 가을 학술발표회 논문집
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    • pp.258-265
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    • 1995
  • For design of seismic isolated system the determination of isolated frequency is very important. In this paper the effects of seismic isolated frequency for cylindrical tank are investigated using the 1940 EL Centre earthquake(NS). From the results of analysis the seismic isolated frequencies significantly depend on input acceleration and displacement components in lower frequency regions. Therefore, the seismic isolated frequency should be determined by consideration of input ground motion characteristics. For the seismic analysis the modified hysteretic hi-linear model of seismic isolators which can consider the yield load variation, shape of hysterisis loop variation and hardening effects of isolators is proposed. The analyses using the proposed model give similar displacement responses but higher maximum acceleration responses than those using the simple hysteretic hi-linear model.

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쓰레기 매립지반의 지진거동 평가 (Seismic Response Evaluation of Waste Landfills)

  • 김기태;이지호;장연수
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2002년도 봄 학술발표회 논문집
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    • pp.767-772
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    • 2002
  • Free-field ground motion during earthquake is significantly affected by the local site conditions and it is essential in the seismic design to perform the accurate site-specific ground response analysis. In this paper, one-dimensional seismic characteristics of waste landfill are studied based on the vertical propagation of horizontal shear waves through the column of soil/waste. Seismic response analysis is peformed for short-period, long-period and artificial earthquake ground motions using a computer program for seismic response analysis of horizontally layered soil deposits. The computed peak ground accelerations are compared with the values calculated according to Korean seismic design guidelines. The analysis result shows that the long-period earthquake causes the largest peak ground acceleration while the artificial earthquake results in the smallest one.

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Seismic behavior of a new type of seismic energy dissipation shear wall system

  • Lu, Xilin;Wu, Xiaohan;Meng, Liang
    • Structural Engineering and Mechanics
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    • 제5권2호
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    • pp.167-175
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    • 1997
  • A new seismic energy dissipation shear wall structure is proposed in this paper. The new shear wall is one with purposely built-in vertical slits within the wall panel, and various seismic energy dissipation devices are installed in the vertical slits so that the dynamic characteristics of the structure (for instance, lateral stiffness, ductility and fundamental period) can be controlled. In order to verify this concept, shaking table tests of two 10-story shear wall models were carried out, and the seismic behavior of the two models are studied by analyzing the test data and computing the nonlinear seismic response of the models.

Effects of the nonlinear behavior of lead-rubber bearings on the seismic response of bridges

  • Olmos, B.A.;Roesset, J.M.
    • Earthquakes and Structures
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    • 제1권2호
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    • pp.215-230
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    • 2010
  • The main objectives of this work were to investigate the effects of the nonlinear behavior of the isolation pads on the seismic response of bridges with rubber bearings, and to identify when base isolation improved their seismic performance. To achieve these objectives a parametric study was conducted designing a set of bridges for three different soil types and varying the number of spans, span lengths, and pier heights. The seismic responses (accelerations, displacements and pier seismic forces) were evaluated for three different structural models subjected to three earthquakes with different dynamic characteristics. The first represented bridges without base isolation; the second corresponded to the same bridges including now rubber bearings as an isolation system, with linear elastic behavior that shifted the natural period of the bridge by a factor of 2 to 4. In the third model the seismic response of bridges supported on lead-Rubber bearings was studied accounting for the nonlinear behavior of the lead. The results show clearly the importance of the nonlinear behavior on the seismic performance of the bridges.

Modifier parameters and quantifications for seismic vulnerability assessment of reinforced concrete buildings

  • Oumedour, Amira;Lazzali, Farah
    • Earthquakes and Structures
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    • 제22권1호
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    • pp.83-94
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    • 2022
  • In recent years, some studies have identified and quantified factors that can increase or decrease the seismic vulnerability of buildings. These modifier factors, related to the building characteristics and condition, are taken into account in the vulnerability assessment, by means of a numerical estimation resulting from the quantification of these modifiers through vulnerability indexes. However, views have differed on the definition and the quantification of modifiers. In this study, modifier parameters and scores of the Risk-UE Level 1 method are adjusted based on the Algerian seismic code recommendations and the reviews proposed in the literature. The adjusted modifiers and scores are applied to reinforced concrete (RC) buildings in Boumerdes city, in order to assess probable seismic damage. Comparison between estimated damage and observed damage caused by the 2003 Boumerdes earthquake is done, with the objective to (i) validate the model involving influence of the modifier parameters on the seismic vulnerability, and (ii) to define the relationship between modifiers and damage. This research may help planners in improving seismic regulations and reducing vulnerability of existing buildings.

Seismic response control of buildings using shape memory alloys as smart material: State-of-the-Art review

  • Eswar, Moka;Chourasia, Ajay;Gopalakrishnan, N.
    • Earthquakes and Structures
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    • 제23권2호
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    • pp.207-219
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    • 2022
  • Seismic response control has always been a grave concern with the damage and collapse of many buildings during the past earthquakes. While there are several existing techniques like base isolation, viscous damper, moment-resisting beam-column connections, tuned mass damper, etc., many of these are succumbing to either of large displacement, near-fault, and long-period earthquakes. Keeping this viewpoint, extensive research on the application of smart materials for seismic response control of buildings was attempted during the last decade. Shape Memory Alloy (SMA) with its unique properties of superelasticity and shape memory effect is one of the smart materials used for seismic control of buildings. In this paper, an exhaustive review has been compiled on the seismic control applications of SMA in buildings. Unique properties of SMA are discussed in detail and different phases of SMA along with crystal characteristics are illustrated. Consequently, various seismic control applications of SMA are discussed in terms of performance and compared with prevalent base isolators, bracings, beam-column connections, and tuned mass damper systems.

도시철도 시설물의 내진성능평가체계에 대한 소고 (Some Thoughts on the Seismic Performance Evaluation Procedure of Urban Railway Infrastructures)

  • 허진호;김진호
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2011년도 춘계학술대회 논문집
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    • pp.1539-1543
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    • 2011
  • Due to recent large earthquakes around the world, there are increasing social needs for seismic safety of urban railway infrastructures. Urban railway infrastructures are applied different seismic performance evaluation procedure each of overground structures, underground structures and bridge structures, and the characteristics of urban railway infrastructures are not properly considered in the procedure. This study presents problems in the existing seismic performance evaluation procedure of urban railway infrastructures and proposes necessities of unified evaluation procedure.

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