• Title/Summary/Keyword: 지진전도모멘트

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A Study on Hybrid Wall System on Connection Type of Coupling Beam (커플링 보의 접합방식에 따른 복합 벽체 시스템에 관한 연구)

  • Yun, Hyun-Do;Park, Wan-Shin;Han, Byung-Chan;Yun, Yeo-Jin
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.7 no.4
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    • pp.201-208
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    • 2003
  • The Hybrid Wall System(HWS) building composed of center core reinforced concrete walls and exterior steel frame has open space around the center core walls. It is necessary to develop design methodologies for the HWS building that the coupled shear walls withstand the most of lateral load and expect the most energy dissipation at the coupling beams and at wall foots. Major factors considered in this paper are connection type of coupling beams and scale of story. The studies of the system are investigated in terms of shear force, overturning moment, maximum lateral displacement, story drift ratio, and dynamical characteristics under the action of vertical and lateral forces such as wind and seismic loads.

Parmanent Grayvity Retaining Wall Displacment Due to Dynamic Loads (동적하중에 의한 중력식 옹벽의 영구변위)

  • 김성교
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.26 no.1
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    • pp.38-51
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    • 1984
  • Mononobe-Okabe에 의해서 옹벽에 대한 동적 토압계산법이 개발된 이래 본론두중 옹벽의 과동에 의한 변위에 대해서는 많은 연구가 이루어졌으나 Mononobe-Okabe식이 원래 옹벽 자체의 관성을 고려치 아니하였고 또 동적 하중의 작용점을 제시하지 않으므로서 전도모멘트를 계산할 수 없게 하므로서 옹벽의 전도에 의한 변위에 대해서는 연구가 되지 아니하였다. 본 연구의 목적은 해석적 방법과 모형실험을 통해서 지진 및 폭파 등의 동적 하중에 의한 옹벽의 전도에 의한 변위를 고찰하고자 하는 바 그 결과를 요약하면 다음과 같다. 1. 활동에 대한 항복가속도가 있는 것과 마찬가지로 전도에 대한 항복가속도가 있다. 이 항복가속도는 옹벽의 안전율이 증가함에 따라 증가한다. 2. 이론치와 실험치는 경향으로 보아 일치한다. 실험치가 이론치보다 작은 것은 모형실험에서 옹벽측면과 컨테이너 사이의 마찰에 기인한 것으로 보아지며 마찰을 줄임으로써 이론치에 더 접근시킬 수 있을 것이다. 3. 옹벽의 회전각도의 크기는 지반가속도가 클수록, 옹벽저면이 작을수록 그리고 흙의 내부마찰각이 작을수록 크게 증가한다. 4. 실용적인 규격의 옹벽의 변위는 활동에 의한 것보다 전도에 의한 것이 훨씬 크며 전체 변위의 대부분을 차지한다. 5. 옹벽 상단의 횡적 변위는 옹벽 설계를 결정짓는 중요한 요소가 될 수 있다.

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Evaluation of Rocking Mechanism for Embedded Shallow Foundation via Horizontal Slow Cyclic Tests (수평반복하중 실험을 이용한 근입된 얕은 기초의 회전거동 메커니즘 평가)

  • Ko, Kil-Wan;Ha, Jeong-Gon;Park, Heon-Joon;Kim, Dong-Soo
    • Journal of the Korean Geotechnical Society
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    • v.32 no.8
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    • pp.47-59
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    • 2016
  • Rocking behavior of shallow foundation reduces the superstructure load during earthquake. However, because of deficiency of understanding of rocking mechanism and soil permanent deformation, it has not been applied to real construction. In this study, slow cyclic tests were conducted for embedded shallow foundations with various slenderness ratio via centrifuge tests. From the variation of earth pressure 'soil rounding surface' phenomenon which makes maximum overturning moment equal to ultimate moment capacity was observed. Rocking and sliding behavior mechanism was evaluated. Also, nonlinear behavior and energy dissipation increase as rotation angle increases. And ultimate moment capacity of embedded foundation is larger than that of surface foundation. Finally, adequate ultimate moment capacity can be suggested for seismic design through this study.

Seismic Design Guidelines for Welded Steel Oil Storge Tank (KS B 6225) (강제석유저장탱크(KS B 6225)의 내진설계기준 개선 안)

  • Park, Jong-Ryul;O, Taek-Yeol
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.3
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    • pp.544-552
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    • 2002
  • Recommended seismic design guide for the flat bottom vortical-cylindrical oil storage tanks in KS B 6225 is presented. Under earthquake excitations, the hydrodynamic pressure exerted on the tank walls produces overturning moment which may cause either a failure of the anchors or a buckling of the tank shell near its base. The basis for establishing design loads due to hydrodynamic pressure is described including seismic zone risk map in Korea, zone coefficients and the essential facilities factor. This procedure for calculating applied compressive stress on the shell base subjecting to seismic load and for estimating the allowable buckling stress is described.

Seismic Design Guidelines for Welded Steel Oil Storge Tank (KS B 6225) (강제 석유 저장 탱크(KS B 6225)의 내진 설계 기준 개선 안)

  • Park, Jong-Ryul;Oh, Taek- Yul
    • Proceedings of the KSME Conference
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    • 2001.11a
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    • pp.166-173
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    • 2001
  • Recommended seismic design guide for the flat bottom vertical-cylindrical oil storage tanks in KS B 6225 is presented. Under earthquake excitations, the hydrodynamic pressure exerted on the tank walls produces overturning moment which may cause either a failure of the anchors or a buckling of the tank shell near its base. The basis for establishing design loads due to hydrodynamic pressure is described including seismic zone risk map in Korea, zone coefficients and the essential facilities factor. This procedure for calculating applied compressive stress on the shell base subjecting to seismic load and for estimating the allowable buckling stress is described.

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Seismic Design Program for Oil Storage Tank (액체저장탱크의 내진설계 프로그램 개발)

  • 박종률;오택열
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1997.10a
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    • pp.551-555
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    • 1997
  • IJnder earthquake excitations, the hydrodynamic pressure exerted on the flat bottom vertical-cylindrical oil storage tank walls produces overturning moment which may cause either a failure of the anchors or a buckling of the tank shell near its base. The basis for establishing design loads due to hydrodynamic pressure is described including seismic zone risk map in Korea. zone coefficients and the essential facilities factor. This procedure for calculating applied compressive stress on the shell base subjecting to seismic load and for estimating the allowable buckling stress is described. And seismic design program for the tanks is presented.

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Seismic Response of a High-Rise RC Bearing-Wall Structure with Irregularities of Weak Story and Torsion at Bottom Stories (저층부에 약층과 비틀림 비정형성을 가진 고층 비정형 RC벽식 구조물의 지진응답)

  • 이한선;고동우
    • Journal of the Earthquake Engineering Society of Korea
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    • v.7 no.6
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    • pp.81-91
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    • 2003
  • Recently, many high-rise reinforced concrete(RC) bearing-wall structures of multiple uses have been constructed, which have the irregularities of weak(or soft) story and torsion at the lower stories simultaneously. The study stated herein was performed to investigate seismic performance of such a high-rise RC structure through a series of shaking table tests of a 1: 12 model. Based on the observations of the test results, the conclusions are drawn as follows: 1) Accidental torsion due to the uncertainty on the properties of structure can be reasonably predicted by using the dynamic analysis than by using lateral force procedure. 2) The mode coupled by translation and torsion induced the overturning moments not only in the direction of excitations but also in the perpendicular direction: The axial forces in columns due to this transverse overturning moment cannot be adequately predicted using the existing mode analysis technique, and 3) the hysteretic curve and the strength diagram between base shear and torque(BST) clearly reveal the predominant mode of vibrations and the failure mode.

Analytical Simulation of the Seismic Response of a High-Rise RC Building Model (고층 철근콘크리트 건축구조모델의 지진응답에 대한 해석적 모사)

  • Lee, Han-Seon;Lee, Jeong-Jae;Jung, Dong-Wook
    • Journal of the Earthquake Engineering Society of Korea
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    • v.12 no.5
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    • pp.1-10
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    • 2008
  • A series of shaking table tests were conducted on a 1:12 scale model using scaled Taft N21E earthquake records to investigate the seismic performance of a 17-story high-rise reinforced concrete building structure with a high degree of torsional eccentricity and soft-story irregularities in the bottom two stories. The main characteristics of the behaviors were: (1) a sudden change of the predominant vibration mode from the mode of translation and torsion to the torsional mode after the flexible side underwent a substantial inelastic deformation; (2) an abrupt increase in the torsional stiffness during this change of modes; (3) a warping behavior of the wall in the torsional mode; and (4) a unilateral overturning moment in the transverse direction to the table excitations. In this study, efforts were made to simulate the above characteristics using a nonlinear analysis program, Perform3D. The advantages and limitations are presented with the nonlinear models available in this software, as they are related to the correlation between analysis and test results.

Structural Performance Assessment of Buildings Considering Beam Discontinuity and Horizontal Irregularity under Wind and Earthquake Loads (보부재 불연속성과 수평비정형성을 고려한 건물의 풍하중과 지진하중에 의한 응답해석)

  • Chakraborty, Sudipta;Islam, Md. Rajibul;Kim, Dookie
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.26 no.5
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    • pp.10-19
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    • 2022
  • Irregularity in structural shape is a ubiquitous phenomenon. Structural hazards evoked from irregularity need to be checked against extreme lateral loadings. Structures containing four distinct types of irregularities in terms of continuity and discontinuity in upper half-length and all story levels along with O-shape are investigated. The structures were analyzed numerically and different seismic responses such as displacements, bending moment, axial forces, torsions, story drift, etc. were scrutinized. The seismic and wind load analysis was conducted for ACI 318-11 conditions. Results show that buildings having discontinuous beams on the upper half exhibit better resilience. It is also concluded that O-shaped building structures provide better resistance to overturning, making this shape relatively safe.

Seismic Soil-Structure Interaction Analyses of LNG Storage Tanks Depending on Foundation Type (기초 형식에 따른 LNG 저장탱크의 지반-구조물 상호작용을 고려한 지진응답 분석)

  • Son, Il-Min;Kim, Jae-Min;Lee, Changho
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.32 no.3
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    • pp.155-164
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    • 2019
  • In this study, the soil-structure interaction(SSI) effect on the seismic response of LNG storage tanks was investigated according to the type of foundation. For this purpose, a typical of LNG storage tank with a diameter of 71m, which is constructed on a 30m thick clay layer over bedrock was selected, and nonlinearity of the soil was taken into account by the equivalent linearization method. Four different types of foundations including shallow foundation, piled raft foundation, and pile foundations(surface and floating types) were considered. In addition, the effect of soil compaction in group piles on seismic response of the tank was investigated. The KIESSI-3D, which is a SSI analysis package in the frequency domain, was used for the SSI analysis. Stresses in the outer tank, and base shear and overturning moment in the inner tank were calculated. From the comparisons, the following conclusions could be made: (1) Conventional fixed base seismic responses of outer tank and inner tank can be much larger than those of considering the SSI effect; (2) The influence of SSI on the dynamic response of the inner tank and the outer tank depends on the foundation types; and (3) Change in the seismic response of the structure by soil compaction in the piled raft foundation is about 10% and its effect is not negligible in the seismic design of the structure.