• Structural Engineering and Mechanics
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• 제52권3호
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• pp.541-558
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• 2014

A 1/4-scale two-bay eight-storey reinforced concrete frame was tested on shaking table. Initial shaking table tests were carried out through a set of real seismic excitations to investigate the seismic behavior of the RC frame. Subsequently, the damaged frame was repaired using epoxy injection technique, and then subjected to the tests with the same records. The purpose of this study was to investigate experimentally the dynamic characteristics, cracking pattern and lateral inter-story stiffness of RC frames using epoxy injection technique. The test results indicate that epoxy-injection technique appears to be a satisfactory method for repairing earthquake-damaged structure.

• Structural Engineering and Mechanics
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• 제17권2호
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• pp.187-201
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• 2004

A shaking table test on a three-story one-bay steel frame model with metallic yield dampers and their parallel connection with oil dampers is carried out to study the dynamic characteristics and seismic performance of the energy dissipation system. It is found from the test that the combined energy dissipation system has favorable reducing vibration effects on structural displacement, and the structural peak acceleration can not evidently be reduced under small intensity seismic excitations, but in most cases the vibration reduction effect is very good under large intensity seismic excitations. Test results also show that stiffness of the energy dissipation devices should match their damping. Dynamic analysis method and mechanics models of these two dampers are proposed. In the analysis method, the force-displacement relationship of the metallic yield damper is represented by an elastic perfectly plastic model, and the behavior of the oil damper is simulated by a velocity and displacement relative model in which the contributions of the oil damper to the damping force and stiffness of the system are considered. Validity of the analytical model and the method is verified through comparison between the results of the shaking table test and numerical analysis.

• Geomechanics and Engineering
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• 제16권5호
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• pp.547-558
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• 2018

Studies of soil dynamic properties in Malaysia are still very limited. This study aims to investigate the dynamic properties of two selected tropical residual soils (i.e., Sandy Clay and Sandy Silt) and a sand mining trail (Silty Sand) in Peninsular Malaysia using 1g shaking table test. The use of 1g shaking table test for soil dynamic testing is often constrained to large strain level and small confining pressure only. Three new experimental setups, namely large laminar shear box test (LLSBT), small chamber test with positive air pressure (SCT), and small sample test with suction (SSTS) are attempted with the aims of these experimental setups are capable of evaluating the dynamic properties of soils covering a wider range of shear strain and confining pressure. The details of each experimental setup are described explicitly in this paper. Experimental results show that the combined use of the LLSBT and SCT is capable of rendering soil dynamic properties covering a strain range of 0.017%-1.48% under confining pressures of 5-100 kPa. The studied tropical residual soils in Malaysia behaved neither as pure sand nor clay, but show a relatively good agreement with the dynamic properties of residual soils in Singapore. Effects of confining pressure and plasticity index on the studied tropical residual soils are found to be insignificant in this particular study.

• 핵의학기술
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• 제21권1호
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• pp.39-43
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• 2017

Thyroglobulin (Tg)은 갑상선에서 특이적으로 생성되는 요오드단백질로써 분화갑상선 암(Differentiate Thyroid Carcinoma, DTC) 의 생물학적 표지자이다. 본 검사실의 Tg 검사법은 반응시간이 길어 진료과와 환자들의 결과보고 요청사항을 만족시키지 못하고 있는 상황이다. 이를 만족시키기 위해 Tg 검사의 반응시간을 단축하고자 현재 사용중인 B사 Kit와 타 병원에서 사용중인 C사 Kit의 반응시간을 단축시켜 실험을 진행하였다. 본원에 의뢰된 Tg 약 65명의 환자 검체를 대상으로 B사 Kit의 반응시간을 $37^{\circ}C$ shaking 2hr/2hr, 실온 shaking 3hr/2hr, $37^{\circ}C$ shaking 1hr/1hr으로, C사 Kit의 원법인 실온 shaking 3hr법과 반응시간을 단축한 실온 shaking 2hr, $37^{\circ}C$ shaking 2hr 방법으로 단축하여 기존에 시행하던 overnight법과 상관성검사를 실시하여 비교하였다. 그 결과 여섯가지 방법 모두 1.0 ng/mL 이상의 값에서는 높은 상관관계를 보였으나 1.0 ng/mL 이하의 값에서는 다소 흔들리는 경향이 있었다. 하지만 그 중 상대적으로 안정적이었던 B사 Kit $37^{\circ}C$ shaking 1hr/1hr 법과 C사 Kit 실온 shaking 2hr 법에 대해 다른 조건들을 재설정하여 적합한 방법을 찾는다면 진료과와 환자들의 요구 사항 충족은 물론, EIA법과의 경쟁력 면에서도 유용할 것이다.

• Nuclear Engineering and Technology
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• 제55권9호
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• pp.3342-3351
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• 2023

High-density polyethylene (HDPE) pipelines in nuclear power plants (NPPs) have to meet high requirements for seismic performance. HDPE pipes have been proved to have good seismic performance, but joints are the weak links in the pipelines, and pipeline failures usually initiate from the defects inside the joints. Limited data are available on the seismic performance of butt-fusion joints of HDPE pipelines in NPPs, especially in terms of defects changes inside the joints after earthquakes. In this paper, full-scale shaking table tests were performed on a test section of suspended HDPE pipelines in an NPP, which included straight pipes, elbows, and 10 butt-fusion joints. During the tests, the seismic load-induced strain of the joints was analyzed by strain gauges, and it was much smaller than the internal pressure and self-weight-induced strain. Before and after the shaking table tests, phased array ultrasonic testing (PA-UT) was conducted to detect defects inside the joints. The locations, numbers, and dimensions of the defects were analyzed. It was found that defects were more likely to occur in elbows joints. No new defect was observed after the shaking table tests, and the defects showed no significant growth, indicating the satisfactory seismic performance of the butt-fusion joints.

• 국제초고층학회논문집
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• 제2권1호
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• pp.79-83
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• 2013

Shaking table test is an important and useful method to help structural engineers get better knowledge about the seismic performance of the buildings with complex structure, just like Shanghai tower. According to Chinese seismic design guidelines, buildings with a very complex and special structural system, or whose height is far beyond the limitation of interrelated codes, should be firstly studied through the experiment on seismic behavior. To investigate the structural response, the weak storey and crack pattern under earthquakes of different levels, and to help the designers improve the design scheme, the shaking table model tests of a scaled model of Shanghai tower were carried out at the State Key Laboratory of Disaster Reduction in Civil Engineering, Tongji University, Shanghai, China. This paper describes briefly the structural system, the design method and manufacture process of the scaled model, and the test results as well.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2009년도 춘계 학술발표회
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• pp.640-648
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• 2009

Recently the truction of coastal reclaimation work has been extensively implemented in Korea. The Sondo New City is being established on the reclaimed land from the sea, construction companies of metro construction are planing to pull-out the sheet pile for saving the construction cost. In the case of soft marine clay, it is very difficult to pull-out the sheet pile by using the hydraulic hammer difficult. Therefore, the man of the field must be aware of vibration effect to the ground and the structure. For understanding the vibration effect to the ground during subway construction, the model was formulated with 1/25 braced-cut for subway construction. Scott and Iai(1989) proposed the law of the similarity for other experimental conditions. The laboratory model test was conducted under the vibration condition of sheet pile pulling out. The settlement on the ground surface was measured during the shaking table test. The pore water pressure was also monitored in the upper, middle, and lower layers of soil. The field settlement level and the pore water pressure can be predicted by using the results of the laboratory shaking table test.

• 콘크리트학회논문집
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• 제18권6호
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• pp.721-728
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• 2006

지진은 구조물에 막대한 피해를 발생시키는 것으로 보고되고 있으나, 우리나라에 내진설계규정이 도입되기 전인 1988년 이전에 설계된 건물은 이에 대한 대책이 없다. 특히 공동주택의 경우 지진저항요소가 없는 구조물이 다수 있는 것으로 조사되었다. 이러한 구조물에 대하여 내진성능의 정도를 파악하고, 성능지수가 부족한 구조물에 대해서는 적절한 보강이 이루어져야 할 것이다. 본 연구에서는 이전의 연구에서 범용 구조해석 프로그램인 MIDAS를 이용하여 모델 구조물의 내진성능을 평가하여 얻어진 내진성능의 부족함을 기초로 5층 규모의 철근콘크리트 벽식 구조물에 상사법칙을 적용하고, 진동대 실험을 수행하여 국내외 규준에 의한 모델 구조물의 내진성능을 평가하였다. 진동대 실험의 경우 실험의 공간적 제약으로 인하여 원형 구조물에 대한 실험을 할 수 없어, 구조물의 원형크기를 상사법칙에 의하여 필요한 규모로 축소하여 제작하였다. 성능수준을 평가해 본 결과 내진설계가 수행되지 않은 구조물은 PGA 등급 0.2g의 지진에 대하여 사용한계수준의 내진성능을 나타내었으며 허용층간변위를 평가해 본 결과 0.2g의 지진등급까지만 허용한계수준의 층간변위를 나타내어 내진성능에 대한 보강이 필요할 것으로 판단되었다.

• 한국구조물진단유지관리공학회 논문집
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• 제5권4호
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• pp.197-203
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• 2001

This study presents the results of shaking table test of scaled model structures with added viscoelastic dampers, which are considered to be one of the most efficient means of upgrading existing structures against seismic loads. The experimental results were compared with those from analysis based on the linear modeling of viscoelastic dampers. The parameters obtained from free vibration test were utilized in the analysis. According to the results the added viscoelastic dampers turned out to be effective in reducing the responses of the model structures. It was also found that the analysis with linear modeling of viscoelastic dampers could simulate the test results accurately.

• 한국전산구조공학회논문집
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• 제20권2호
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• pp.217-225
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• 2007

본 연구에서는 건물모델만을 물리적인 실험체로 이용하여 동적 지반강성을 갖는 지반-구조물계의 동적거동을 모사하기 위한 하이브리드 진동대 실험법을 제안하고 이를 실험적으로 검증하였다. 본 연구에서 제안되는 실험방법은 상부구조물과 진동대의 가속도를 계측하여 진동대 제어기로 피드백하고, 전체 지반-구조물계의 동적거동을 묘사하기 위해 요구되는 기초부분의 절대가속도 응답(가속도 피드백 방법) 또는 절대속도 응답(속도 피드백 방법)을 계산하여 진동대를 구동시키는 방법이다. 지반부분을 계산하기 위해서 이론적인 동적지반강성을 제안방법에 따라서 다르게 근사화하여 진동대 제어기에 반영함으로써 실험을 수행하였다. 기초 고정계 모델에 대한 실험으로부터 계측된 응답과 본 논문에서 가정한 지반-구조물 계에 대한 실험으로부터 측정된 응답을 비교하고, 진동대 제어기에 반영한 동적지반강성과 실험데이터를 이용하여 식별된 동적지반강성을 비교함으로써 본 논문에서 제안된 실험방법의 유효성을 검증하였다.