• Title/Summary/Keyword: ground response analysis

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Study on the Improvement of Response Spectrum Analysis of Pile-supported Wharf with Virtual Fixed Point (가상고정점기법이 적용된 잔교식 구조물의 응답스펙트 럼해석법 개선사항 도출 연구)

  • Yun, Jung Won;Han, Jin Tae
    • Journal of the Earthquake Engineering Society of Korea
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    • v.22 no.6
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    • pp.311-322
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    • 2018
  • As a method of seismic-design for pile-supported wharves, equivalent static analysis, response spectrum analysis, and time history analysis method are applied. Among them, the response spectrum analysis is widely used to obtain the maximum response of a structure. Because the ground is not modeled in the response spectrum analysis of pile-supported wharves, the amplified input ground acceleration should be calculated by ground classification or seismic response analysis. However, it is difficult to calculate the input ground acceleration through ground classification because the pile-supported wharf is build on inclined ground, the methods to calculate the input ground acceleration proposed in the standards are different. Therefore, in this study, the dynamic centrifuge model tests and the response spectrum analysis were carried out to calculate the appropriate input ground acceleration. The pile moment in response spectrum analysis and the dynamic centrifuge model tests were compared. As a result of comparison, it was shown that the response spectrum analysis results using the amplified acceleration in the ground surface were appropriate.

Effect of Input Soil Properties for Round Robin Test on Ground Response Analysis (지반 응답 해석 Round Robin Test의 입력 지반 물성에 따른 지반 응답 특성 영향 고찰)

  • Kim, Bong-Soo;Lee, Sei-Hyun;Choo, Yun-Wook;Park, Sung-Sik;Kim, Dong-Joon
    • Proceedings of the Korean Geotechical Society Conference
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    • 2007.09a
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    • pp.305-316
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    • 2007
  • Free field ground motion during earthquake is significantly affected by the local soil conditions and it is essential for the seismic design to perform the site specific ground response analysis. So, Round Robin Test (RRT) on ground response analysis was performed for three sites in Korea. A total of 12 teams presented the results of ground response analysis with used input soil properties based on own judgement. In this paper, the results of one dimensional equivalent linear analysis presented by 11 teams were compared to evaluate the effect of input soil properties on ground response analysis. Additionally, 4 influence factors on ground response analysis, that is shear wave velocity of soil layer, nonlinear dynamic deformational characteristics, bedrock depth and bedrock velocity were studied for assumed simple soil conditions.

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Seismic analysis of shear wall buildings incorporating site specific ground response

  • Jayalekshmi, B.R.;Chinmayi, H.K.
    • Structural Engineering and Mechanics
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    • v.60 no.3
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    • pp.433-453
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    • 2016
  • During earthquake, the motion of ground is affected significantly by source characteristics, source-to-site path properties and local site conditions. Due to the influence of local soil conditions different places experience distinctive amplitude of surface ground motion. Ground response analysis of a specific site utilizing the borehole information at different locations is done in present study. The ground motion with the highest peak ground acceleration for this site obtained from the ground response analysis is used in finite element soil-structure interaction analysis of multi-storey shear wall buildings with various positions of shear walls. The variation in seismic response of buildings and advantageous position of shear wall are determined. The study reveals that providing shear wall at the core of buildings at the specific site is advantageous among all shear wall configurations considered.

Ground Response Curve for Ground Movement Analysis of Tunnel (지반응답곡선을 이용한 터널의 지반거동 분석)

  • Lee, Song;Ahn, Sung-Hak;Ahn, Tae-Hun;Kong, Sung-Suk
    • Journal of the Korean Society for Railway
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    • v.5 no.4
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    • pp.244-252
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    • 2002
  • We must notice ground movement by excavation for reasonable tunnel designs. The convergence confinement method is an attempt to evaluate tunnel stability conditions by means of a mathematical model and a ground response curve. In this study, the convergence confinement method by numerical model was examined. This method don't need the basic assumptions for a mathematical model of circular tunnel shape, and hydrostatic in situ stress. Also modified ground response curve that is calculated after installing the support, is suggested, which informs us the ground movement mechanism. The ground response curve and the support reaction curve are mutually dependent. Especially the support reaction curve depends upon the ground response curve. The mechanism of tunnel must be analyzed by the interaction between support and ground. Consequently the stability of tunnel must be qualitatively investigated by a ground response curve and quantitatively adjudged by a numerical analysis for the reasonable design of tunnel.

Probabilistic Analysis of Liquefaction Cyclic Stress Ratio Considering Soil Variability (지반변동성을 고려한 액상화 진동전단응력비의 확률론적 해석)

  • Heo, Joon
    • Journal of The Korean Society of Agricultural Engineers
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    • v.60 no.2
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    • pp.95-101
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    • 2018
  • The objective of this study is to evaluate the liquefaction cyclic shear stress ratio considering the soil uncertainty. In this study, the probabilistic ground response analysis and the cyclic shear stress ratio analysis for the liquefaction potential evaluation are performed considering the soil variability. The statistical properties of input ground parameters were analyzed to investigate the parameters affecting the seismic response analysis. The Probabilistic analysis was carried out by Monte Carlo Simulation method. The ground response analysis was performed considering the soil variability and the probability distribution characteristics of the ground acceleration. The probability distribution of the peak ground acceleration by seismic characteristics was presented. The differences of liquefaction shear stress ratio results according to soil variability were compared and analyzed. The maximum acceleration of the ground by the deterministic method was analyzed to be overestimation of the ground amplification phenomenon. Also, the shear stress ratio was overestimated.

Seismic Fragility Analysis of NPP Components for High Frequency Ground Motions (고진동수 지진동에 대한 원전 기기의 지진취약도 분석)

  • 최인길;서정문;전영선
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2003.03a
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    • pp.110-117
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    • 2003
  • The result of recent seismic hazard analysis indicates that the ground motion response spectra for Korean nuclear power plant site have relatively large high frequency acceleration contents. In the ordinary seismic fragility analysis of nuclear power plant structures and equipments, the safety margin of design ground response spectrum is directly used as a response spectrum shape factor. The effects of input response spectrum shape on the floor response spectrum were investigated by performing the direct generation of floor response spectrum from the ground response spectrum. The safety margin included in the design ground response spectrum should be considered as a floor response spectrum shape factor for the seismic fragility analysis of the equipments located in a building.

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Comparative Study on Ground Response Analyses for Seismic Design of Geotechnical Structures (지반 구조물의 내진설계를 위한 지반응답해석 기법의 비교연구)

  • Hwang, Jae-Ik;Han, Jin-Tae;Cho, Jong-Seok;Kim, Myoung-Mo
    • Proceedings of the Korean Geotechical Society Conference
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    • 2005.03a
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    • pp.294-301
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    • 2005
  • Ground response analysis is one of the most important and most commonly encountered problems in geotechnical earthquake engineering. It is a prerequisite step for liquefaction assessment of saturated soil or the pseudo-static and dynamic analysis of geotechnical structures. A number of techniques have been developed for ground response analysis. In this study, ground response analyses were performed using the computer programs that are currently being used domestically. From these analyses, the analysis techniques applied to the programs were compared and analyzed. The results of ground response analyses were compared as follows: 1) 1-dimensional analysis vs. 2-dimensional analysis; 2) equivalent linear analysis vs. nonlinear analysis.

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Study on Improvement of Response Spectrum Analysis of Pile-supported Structure: Focusing on the Natural Periods and Input Ground Acceleration (잔교식 구조물의 응답스펙트럼 해석법 개선사항 도출 연구: 고유주기 및 입력지반가속도를 중점으로)

  • Yun, Jung-Won;Han, Jin-Tae;Kim, Jong-Kwan
    • Journal of the Korean Geotechnical Society
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    • v.36 no.6
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    • pp.17-34
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    • 2020
  • In response spectrum analysis of pile-supported structure, an amplified seismic wave should be used as the input ground acceleration through the site-response analysis. However, each design standard uses different input ground acceleration criteria, which leads to confusion in determining the appropriate input ground acceleration. In this study, the ground accelerations were calculated through dynamic centrifuge model test, and the response spectrum analysis was performed using the calculated ground acceleration. Then, the moments derived from the test and analysis were compared, and a method for determining the appropriate input ground acceleration in response spectrum analysis was presented. Comparison of the experimental and simulated results reveals that modeling of the ground using elastic springs allows proper simulation of the natural period of the structure, and the use of a seismic wave that is amplified at the ground surface as the input ground acceleration provided the most accurate results for the response analysis of pile-supported structures in sands.

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

  • 김기태;이지호;장연수
    • Proceedings of the Korean Geotechical Society Conference
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    • 2002.03a
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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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Influence of Analysis Models on Variation of Ground Response during Earthquake (지반응답해석기법의 차이에 의한 지반응답 분산도 평가)

  • Kim, Sung-Ryul;Choi, Jae-Soon;Kim, Soo-Il;Park, Dae-Young;Park, Seong-Yong;Kim, Ki-Poong
    • Proceedings of the Korean Geotechical Society Conference
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    • 2007.09a
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    • pp.317-333
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    • 2007
  • The Round-Robin Test (RRT) for ground response analysis was performed by Division of Geotechnical Earthquake Engineering of Korean Geotechnical Society. This research analyzed the influence of analysis methods on variation of ground response by using the results of this RRT. The analysis methods include equivalent linear analysis, non-linear analysis and effective stress analysis. A total of 5 teams among 12 teams applied two kinds of analysis methods. This research compared the results of these 5 teams and analyzed the variation of the results according to analysis methods. The compared results were shear stress-shear strain relation, transfer function, time history and the response spectrum of ground surface acceleration, peak ground acceleration, peak shear strain and maximum excess pore pressure ratio.

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