• Title/Summary/Keyword: shaking table study

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Study for Dynamic Response of EDF System (EDF 시스템의 동적거동 특성에 관한 연구)

  • 한규승;박선규;김남식
    • Proceedings of the Korea Concrete Institute Conference
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    • 1999.10a
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    • pp.399-402
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    • 1999
  • This study is about seismic performance of the EDF(Electricite De France) system, that is among various base isolator. We get solutions of equation of motion of this system for displacement, velocity, acceleration and compared with solutions using finite element program. And, through shaking table tests we will prove seismic performance

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Experimental Study of Friction Pendulum System to Improve the Seismic Capacity of Transformer (변압기의 내진성능 향상을 위한 마찰진자 면진장치의 시험 연구)

  • Jang, Jung-Bum;Kim, Jeong-Ki;Hwang, Kyeong-Min;Ham, Kyung-Won;Park, Jin-Wan;Lee, Chan-Wook
    • Journal of the Earthquake Engineering Society of Korea
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    • v.12 no.2
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    • pp.1-8
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    • 2008
  • Friction pendulum system is developed to prevent the damage of transformer, which is the most important among the electric power facilities, due to the earthquake and its seismic capacity is verified through the shaking table test. The applicability of friction pendulum system is confirmed as test results of compressive capacity test and friction test. Especially, as a result of shaking table test with a large scale transformer model, friction pendulum system gives to the reduction of maximum response acceleration by 30% at anchorage of transformer and 59% at the top of porcelain bushing comparing with the existing anchorage type. In addition to the reduction of maximum response acceleration, natural frequency of transformer is shifted to long period due to the friction pendulum system. In case that friction pendulum system is applied to the transformer, the damage of transformer can be prevented effectively under the earthquake.

A Study on the Nonlinear Modeling of Lead Rubber Bearings by a Neural Network Theory (신경망 이론을 적용한 납삽입 적층 고무베어링의 비선형 모델링 기법에 관한 연구)

  • Huh, Young-Cheol;Kim, Young-Joong;Kim, Byung-Hyun
    • Journal of the Earthquake Engineering Society of Korea
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    • v.8 no.4
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    • pp.63-69
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    • 2004
  • In this paper, a nonlinear modeling of lead rubber bearings(LRBs) was presented by a neural network theory. An shaking table test for a scaled frame model, of which base was isolated by the LRBs, was performed to verify numerical accuracies of the neural network model. White noise and three types of seismic records were adoped as base loads of the shaking table in order to train and generalize the neural network in case of seismic loads, numerical results of the neural network model were evaluated according to different magnitudes of PGA. As results, it is concluded that the presented neural network model has given a good agreement with the experimental data in details and can be useful to a nonlinear modeling of LRBs within prescribed domains.

Response Characteristic of the Dual-frame Passive Control System with the Natural Period Difference between the Strength Resistant Core and Frame Structure (강도저항형 코어와 프레임 구조의 진동주기차를 이용한 듀얼프레임 제진시스템의 응답특성)

  • Kim, Tae Kyung;Choi, Kwang Yong;Oh, Sang Hoon;Ryu, Hong Sik
    • Journal of the Earthquake Engineering Society of Korea
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    • v.19 no.6
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    • pp.273-282
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    • 2015
  • In this study, shaking table test has been carried out for the dual frame passive control system for seismic performance verification of the proposed system. The proposed system was separated into two independent frameworks that are strength resistant core and frame structure by connecting to the damper. Moreover, the seismic performance improvement of the proposed system has been verified by comparing and analyzing the experimental results of the proposed system with an existing core system. As a result of the shaking table test, acceleration and displacement responses of dual-frame vibration control system are decreased than those of the existing strength resistant type core system. In the case of the core system, while the damage was concentrated on the column of first floor, the damage of the dual system was dispersed in each layer. The damage also was concentrated on the damper, almost no damage occurs to the structural members. It has been emphasized that installed dampers in the proposed dual system reduce the input energy of whole structure by absorbing seismic input energy, which leads overall system damage to be reduced.

Evaluation of numerical procedures to determine seismic response of structures under influence of soil-structure interaction

  • Tabatabaiefar, Hamid Reza;Fatahi, Behzad;Ghabraie, Kazem;Zhou, Wan-Huan
    • Structural Engineering and Mechanics
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    • v.56 no.1
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    • pp.27-47
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    • 2015
  • In this study, the accuracy and reliability of fully nonlinear method against equivalent linear method for dynamic analysis of soil-structure interaction is investigated comparing the predicted results of both numerical procedures with the results of experimental shaking table tests. An enhanced numerical soil-structure model has been developed which treats the behaviour of the soil and the structure with equal rigour. The soil-structural model comprises a 15 storey structural model resting on a soft soil inside a laminar soil container. The structural model was analysed under three different conditions: (i) fixed base model performing conventional time history dynamic analysis, (ii) flexible base model (considering full soil-structure interaction) conducting equivalent linear dynamic analysis, and (iii) flexible base model performing fully nonlinear dynamic analysis. The results of the above mentioned three cases in terms of lateral storey deflections and inter-storey drifts are determined and compared with the experimental results of shaking table tests. Comparing the experimental results with the numerical analysis predictions, it is noted that equivalent linear method of dynamic analysis underestimates the inelastic seismic response of mid-rise moment resisting building frames resting on soft soils in comparison to the fully nonlinear dynamic analysis method. Thus, inelastic design procedure, using equivalent linear method, cannot adequately guarantee the structural safety for mid-rise building frames resting on soft soils. However, results obtained from the fully nonlinear method of analysis fit the experimental results reasonably well. Therefore, this method is recommended to be used by practicing engineers.

Shaking table test for analysis of seismic performance of cut and cover tunnel using EPS block as backfill material (개착식 터널의 뒤채움재로 EPS블럭의 내진 성능 평가를 위한 진동대 시험)

  • Kim, Nag-Young;Lee, Yong-Jun;Lee, Seung-Ho;Chung, Hyung-Sik
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.4 no.4
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    • pp.333-342
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    • 2002
  • World widely, the occurrences of earthquakes have been increased recently. Speculating from cases of earthquakes in the world, it is reported that damages have been made underground structures like cut-and-cover tunnels, especially on the upper of tunnel with a shallow depth and the backfilled area adjacently by earthquakes. Earthquakes have a tendency to increase recently in Korea but it is deficient in seismic design criteria. In this study, Shaking table test on both soil and EPS blocks was performed to analyze the efficiency of the seismic performance of the cut-and-cover tunnels according to characteristic of backfill materials and embanking material. It turned out to be effective in improving the seismic performance according to analysis of strain and bending stress of tunnel by earthquakes.

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Estimation of Dynamic Properties of Steel Liquid Storage Tank by Shaking Table Test (진동대 실험에 의한 강재 액체저장탱크의 동특성 분석)

  • Choi, Hyoung Suk;Park, Dong Uk;Kim, Sung Wan;Kim, Jae Min;Baek, Eun Rim
    • Journal of the Earthquake Engineering Society of Korea
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    • v.21 no.4
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    • pp.153-161
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    • 2017
  • Liquid storage tank is one of the major infrastructures and generally used to store gases, drinking and utilizing water, dangerous fluids, fire water and so on. According to the recent reports and experiences, the tank structures are damaged in many earthquakes due to their low energy dissipating capacity. Therefore, many researchers have been tried to know the dynamic properties of the tanks including liquids. However, vary limited experimental studies are carried out using relatively small tank models. In this study, a series of shaking table tests are performed with maximum 2 m cubic rectangular liquid storage tanks made of steel to measure the natural frequency and estimate damping coefficient of impulsive and convective mode of the tanks. Especially, the damping values under different shapes and excitation methods are estimated by logarithmic decrement method and half power band-pass method and compared with current design code and standards such as ASCE 7, Eurocode 8 and NZS. Test results show that the impulsive mode damping is around 2% which is proposed by general standards and codes but the impulsive mode damping is 0.13% average that is slightly lower than the code recommendation.

Estimation of Dynamic Interface Friction Properties of Geosynthetics (토목섬유의 동적 경계면 마찰특성 평가)

  • 김동진;서민우;박준범;박인준
    • Journal of the Korean Geotechnical Society
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    • v.19 no.4
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    • pp.265-275
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    • 2003
  • In this study, shaking table tests were conducted to estimate dynamic interface properties between geosynthetics such as geomembrane, geotextile and geosynthetic clay liner. Accelerations of both shaking table and upper box, and relative displacements between geosynthetics under dynamic loading were measured. Also, the influence of normal stress, frequency of excitation and dry/wet conditions were investigated through the analyses of test results. from the test results, it was found that there is a limited acceleration below which dynamic farce can be transmitted between geosynthetics without the loss of horizontal acceleration. Dynamic interface friction angle between geosynthetics could be calculated through the limited acceleration. Relative displacements induced along geosynthetic interfaces under dynamic loading were not consistent depending on the type of interface and test conditions. The maximum slip displacements between geosynthetics are normalized and normalized slip equations were developed for each interface. By using the normalized slip equation, maximum slip displacements for the geosynthetic interface could be predicted for the given base acceleration and frequency of excitation.

Constrained Effect of Soil Nail Head on the Earthquake Load (지진하중에 의한 쏘일네일 두부구속효과)

  • Oh, Joungkeun;Kang, Hongsig;Ahn, Kwangkuk
    • Journal of the Korean GEO-environmental Society
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    • v.14 no.2
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    • pp.43-50
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    • 2013
  • In this study, the tests were carried out for the behavior according to method of constrained nail head of slope reinforced with soil nail under dynamic loading, by using shaking table. Shaking table tests were carried out by applying Hachinohe seismic wave having the long-period characteristics and Ofunato seismic wave having short-period characteristics, as changing constrained and unconstrained condition of nail head, and so on. Failure mode, ground acceleration characteristics, vertical displacement and horizontal displacement of slope were compared and analyzed on the basis of results obtained from the test. Results of carrying out shaking table test showed that both short-period wave and long-period wave had large effects on slope, and constraint of nail head was found to have large shear resistance for dynamic load. And it was confirmed that stability of slope under seismic loading was largely improved by constrained head of soil nail.

Experimental Study on Seismic Performance Evaluation of Lake Dike Structures under Earthquake Loading (지진하중에 의한 방수제 구조물의 내진성능 평가를 위한 실험적 연구)

  • Shin, Eun-Chul;Kang, Hyeon-Hoe;Kim, Tae-Jin;Chae, Young-Su;Park, Jeong-Jun
    • Journal of the Korean Geosynthetics Society
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    • v.10 no.3
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    • pp.53-62
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    • 2011
  • This paper presents the characteristics behavior of dike structure and foundation ground through the shaking table model test. The vibration loadings of design earthquake acceleration of 0.154g was applied to this laboratory model test regarding on dike structure and foundation ground under the structure. The model was formulated with 1/100 design of representative cross section for evaluating the effectiveness of vibration. Based on the test results, we can analysis the behavior of lateral displacement and settlement characteristics of structure under the earthquake loading. The pore water pressure was also monitored in the upper, middle and lower layers of ground. Finally, the actual displacements and pore water pressure of the structure can be predicted by using the results of the laboratory shaking table test.