• Title/Summary/Keyword: Seismic condition

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A Seismic Analysis of Spent Fuel Handling Tool (사용후 핵연료 취급장비의 내진해석)

  • 김성종;이영신;김재훈;김남균
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2002.05a
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    • pp.1210-1215
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    • 2002
  • The spent fuel handling tool is used to handle the refuel bundle and treated by hoist rope on the bridge crane. The new developed handling tool of NPP(Nuclear Power Plant) should be conformed the structural stability under earthquake condition. In this study, the stress and seismic analysis of the handling tool are performed by finite element method. Using the Floor Response Spectrum(FRS) obtained through the time history analysis, the modal and seismic analysis under Operating Basis Earthquake(OBE) and Safe Shutdown Earthquake(SSE) load conditions are carried out. Total 4 cases of different locations of the trolly and the hook are investigated. With the spring-damper element, the tension analysis of hoist rope is conducted. The stability of handling tool under earthquake load condition is conformed with regulatory guide.

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MODEL TESTS ON LEVEES REINFORCED WITH SHEET PILES UNDER HIGH WATER CONDITIONS WITH/WITHOUT SEISMIC LOADING HISTORY

  • Koseki, Junichi;Tanaka, Hiroyuki;Otsushi, Kazutaka;Nagao, Naoya;Kaneko, Masaru
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.09c
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    • pp.49-54
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    • 2010
  • In order to study the performance of levees reinforced with steel sheet piles under high water condition, a series of model tests was conducted by simulating the high water condition before and after applying severe seismic loading history. As a result, the seepage behavior through the subsoil layers underlying the levee was not significantly affected by the seismic loading history. It was also verified that, irrespective of the seismic loading history, the sheet piles installed at the levee crest or shoulder are effective in preventing the breakage of levees caused by overflow. In addition, applicability of drainage works at the foot of the levee in preventing the seepage failure was confirmed.

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Seismic Response Control of Retractable-roof Spatial Structure Using Smart TMD (스마트 TMD를 이용한 개폐식 대공간 구조물의 지진응답제어)

  • Kim, Hyun-Su;Kang, Joo-Won
    • Journal of Korean Association for Spatial Structures
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    • v.16 no.4
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    • pp.91-100
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    • 2016
  • A retractable-roof spatial structure is frequently used for a stadium and sports hall. A retractable-roof spatial structure allows natural lighting, ventilation, optimal conditions for grass growth with opened roof. It can also protects users against various weather conditions and give optimal circumstances for different activities. Dynamic characteristics of a retractable-roof spatial structure is changed based on opened or closed roof condition. A tuned mass damper (TMD) is widely used to reduce seismic responses of a structure. When a TMD is properly tuned, its control performance is excellent. Opened or closed roof condition causes dynamic characteristics variation of a retractable-roof spatial structure resulting in off-tuning. This dynamic characteristics variation was investigated. Control performance of a passive TMD and a smart TMD were evaluated under off-tuning condition.

Seismic Evaluation of Ordinary Moment Concrete Frames Using Capacity Spectrum Method (지반특성과 지진지역에 따른 보통모멘트 골조의 내진성능 평가)

  • 권건업;한상환
    • Proceedings of the Korea Concrete Institute Conference
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    • 2001.11a
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    • pp.947-952
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    • 2001
  • This study is to evaluate seismic performance of ordinary moment concrete frames. Base shear and roof displacement relations are obtained from the experiment of 3 story ordinary moment resisting concrete frame. The frame was designed only for gravity loads. The performance of the building is evaluated using capacity spectrum method. Five different seismic zones and three different soil types are considered. For each condition of seismic zone and soil type, ten earthquake ground motions are used to establish the demand spectrum.

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The Study of Seismic Design for Underground RC Structure (지하 철근콘크리트 구조물의 내진설계에 관한 연구)

  • 조병완;문병옥;태기호;안제상
    • Proceedings of the Korea Concrete Institute Conference
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    • 2002.05a
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    • pp.867-872
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    • 2002
  • The seismic design from the underground structures with the ground structures differently relative acceleration of ground and structure for, that period ci it was a condition where the recognition against the seismic design of the underground structure is insufficient because the decease damage does not very to that extent. Analysis result, earthquake hour section power increase one that price smiles from one part and when it applies a regular design hour safety rate 20%, seismic efficiency level satisfaction is it becomes feed with the fact that it will be able to augment the efficient characteristic of design.

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Significant Changes in the Seismic Design Provisions of the 2005 KBC (KBC 2005 내진설계 주요 개정사항)

  • Chung, Kwang-Rhang;Yoo, Byoung-Eok
    • Journal of the Korean Professional Engineers Association
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    • v.38 no.5
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    • pp.5-9
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    • 2005
  • The seismic design provisions of the 2005 KBC has been based on the 2000 IBC and has considered the building code situations in Korea. There are site ground motion, soil class, seismic design category in the significant changes of the 2005 KBC. In the case of soft soil condition, the response spectrum acceleration of the 2005 KBC is larger than that of previous code. To reduce the seismic force of the 2005 KBC, it need to introduce the eqrthauke force resisting system with high ductility.

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Energy dissipation system for earthquake protection of cable-stayed bridge towers

  • Abdel Raheem, Shehata E.;Hayashikawa, Toshiro
    • Earthquakes and Structures
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    • v.5 no.6
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    • pp.657-678
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    • 2013
  • For economical earthquake resistant design of cable-stayed bridge tower, the use of energy dissipation systems for the earthquake protection of steel structures represents an alternative seismic design method where the tower structure could be constructed to dissipate a large amount of earthquake input energy through inelastic deformations in certain positions, which could be easily retrofitted after damage. The design of energy dissipation systems for bridges could be achieved as the result of two conflicting requirements: no damage under serviceability limit state load condition and maximum dissipation under ultimate limit state load condition. A new concept for cable-stayed bridge tower seismic design that incorporates sacrificial link scheme of low yield point steel horizontal beam is introduced to enable the tower frame structure to remain elastic under large seismic excitation. A nonlinear dynamic analysis for the tower model with the proposed energy dissipation systems is carried out and compared to the response obtained for the tower with its original configuration. The improvement in seismic performance of the tower with supplemental passive energy dissipation system has been measured in terms of the reduction achieved in different response quantities. Obtained results show that the proposed energy dissipation system of low yield point steel seismic link could strongly enhance the seismic performance of the tower structure where the tower and the overall bridge demands are significantly reduced. Low yield point steel seismic link effectively reduces the damage of main structural members under earthquake loading as seismic link yield level decreases due their exceptional behavior as well as its ability to undergo early plastic deformations achieving the concentration of inelastic deformation at tower horizontal beam.

Seismic Analysis of 30/5 Ton Overhead Crane for 30MWTh Korea Multipurpose Research Reactor (KMRR) (다목적연구용 원자로의 30/5 톤 천정크레인에 대한 지진해석에 관한 연구)

  • Yoo, Bong;Suh, Ki-Suk;Chu, Yong-Sun;Hong, Sung-In
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1991.10a
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    • pp.111-114
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    • 1991
  • The KMRR 4-wheel crane which has a span of 30.6m long shall be designed to maintain its structural integrity during and after seismic shocks. Horizontal and vertical FRS for OBE and SSE conditions at the crane support are after seismic shock. Horizontal and vertical FRS for analysis are 4% for OBE and 7% for SSE. The crane consists of girder, saddle main and auxiliary trolley, and necessaries. They are modeled as beam elements and lumped masses for the following 4 cases ; trolley at center of the crane with and without the rated load, trolley at end with and without the rated load. The static analysis as well as the linear dynamic analysis including frequency and response spectrum analysis are performed for the seismic qualification of the crane using the Finite Element Method. For the simplicity of the analysis, the decoupling criteria are considered for the crane rope and the crane supporting beams. The main sections of the crane are stiffened until the calculated stresses satisfy the allowable limits. The seismic resultant loads are used to design the seismic restraints of the saddle and the trolley to protect the clue from the seismic uplifting loads the study results have show that the seismic design of the KMRR crane is governed by the OBE condition. not by the SSE condition. This paper briefly describes the analysis procedure used in the seismic design of the KMRR crane, and summarizes the analysis results.

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Seismic effects of epicenter distance of earthquake on 3D damage performance of CG dams

  • Karalar, Memduh;Cavusli, Murat
    • Earthquakes and Structures
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    • v.18 no.2
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    • pp.201-213
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    • 2020
  • Seismic damages that occurred by the effects of epicenter distance of the earthquake are one of the most important problems for the earthquake engineering. In this study, it is aimed to examine the nonlinear seismic behaviors of concrete gravity (CG) dams considering various epicenter distances. For this purpose, Boyabat CG dam that is one of the biggest concrete gravity dams in Turkey is selected as a numerical application. FLAC3D software based on finite difference method is used for modelling and analyzing of the dam. Drucker-Prager nonlinear material model is used for the concrete body and Mohr-Coulomb nonlinear material model is taken into account for the foundation. Special interface elements are used between dam body and foundation to represent interaction condition. Free-field and quiet non-reflecting boundary conditions are utilized for the main surfaces of 3D model. Total 5 various epicenter distances of 1989 Loma Prieta earthquake are considered in 3D earthquake analyses and these distances are 5 km, 11 km, 24 km, 85 km and 93 km, respectively. According to 3D seismic results, x-y-z displacements, principal stresses and shear strain failures of the dam are evaluated in detail. It is clearly seen from this study that the nonlinear seismic behaviors of the CG dams change depending to epicenter distance of the earthquake. Thus, it is clearly recommended in this study that when a CG dam is modelled or analyzed, distance of the earthquake fault to the dam should be strongly examined in detail. Otherwise, earthquake damages can be occurred in the concrete dam body by the effects of seismic loads.

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

  • Oumedour, Amira;Lazzali, Farah
    • Earthquakes and Structures
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    • v.22 no.1
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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.