• Journal of the Korea institute for structural maintenance and inspection
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• v.26 no.1
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• pp.10-18
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• 2022

This report describes the development and stability evaluation of a seismic retrofit method to evaluate the seismic performance of existing school buildings by analyzing the earthquake waveforms that occurred in Korea. Currently, Facilities for seismic retrofit designed for excessive reinforcement are being applied. To compensate for this, optimised the retrofit mothod suitable for domestic situation considering the characteristics of the seismic region, generated a Korean-style artificial seismic wave that meets the seismic design criteria, which is less frequent than other countries.

• Journal of the Korean GEO-environmental Society
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• v.12 no.4
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• pp.53-63
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• 2011

Selection or generation of appropriate input ground motion is very important in performing a dynamic analysis. In Korea, it is a common practice to use recorded strong ground motions or artificial motions. The recorded motions show non-stationary characteristics, which is a distinct property of all earthquake motions, but have the problem of not matching the design response spectrum. The artificial motions match the design spectrum, but show stationary characteristics. This study generated ground motions that preserve the non-stationary characteristics of a real earthquake motion, but also matches the design spectrum. In the process, an impulse function-based algorithm that adjusts a given time series in time domain such that it matches the target response spectrum is used. Application of the algorithm showed that it can successfully adjust any recorded motions to match the target spectrum and also preserve the non-stationary characteristics. The modified motions are used to perform a series of nonlinear site response analyses. It is shown that the results using the adjusted motions result in more reliable estimates of ground vibration. It is thus recommended that the newly adjusted motions be used in practice instead of original recorded motions.

• Journal of the Korean Society for Advanced Composite Structures
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• v.2 no.4
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• pp.28-34
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• 2011

Because strong urban earthquakes must produce huge losses of both life and property, examinations about the effect of huge earthquakes for tall buildings are very required. The goal of this report is examining model safety and compare the behavior of 2-D tall models under huge seismic loads. This report examines high-rise models designed KBC2009 codes using 1) seismic loads regulated by KBC2009 and 2) amplified seismic loads assumed to strong earthquakes. And observing for more realistic behavior of tall buildings under huge earthquakes, this report takes two analysis methods - response spectrum analysis and non-linear time history analysis considering P-delta effect.

• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.2
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• pp.347-360
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• 2018

Due to the concentration and congestion of traffic in Seoul metropolitan area, effective utilization of underground space is required, and construction of various underground structures such as a double deck tunnel is increasing. Double deck tunnels are divided into upper and lower runways, and the most important part is middle slab. To investigate seismic behavior of middle slab, experimental study is required because of the complexity of the load and the mechanism of earthquake. In this study, centrifugal model tests were conducted to investigate the response characteristics of earthquake response according to the support conditions of the middle slab of a double deck tunnel. Artificial, Ofunato (short period) and Hachinohe (long period) seismic waves were employed in the experimental study. As a result, it was confirmed that the acceleration attenuation of elastomeric bearings condition was 10.6% in artificial earthquake, 13.6% in Ofunato earthquake, and 10.3% in Hachinohe earthquake. The results indicate that elastomeric bearings have some advantages in the viewpoint of seismic behaviors.

• Journal of the Earthquake Engineering Society of Korea
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• v.10 no.5 s.51
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• pp.11-23
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• 2006

This paper evaluates the seismic response of multi-span prestressed concrete girder bridges typically found in the New Madrid Seismic Zone region of the central United States. Using detailed nonlinear analytical models and synthetic ground motion records for Memphis, TN, nonlinear response history analyses are performed for two levels of ground motion: 10% probability of exceedance (PE) in 50 years, and 2% probability of exceedance (PE) in 50 years. The results show that the bridge performance is very good fur the 10% PE in 50 years ground motion level. However, the performance for the 2% PE in 50 years ground motion is not so good because it results in highly inelastic behavior of the bridge. Impact between decks results in large ductility demands on the columns, and failure of the bearings that support the girders. It is found that making the superstructure continuous, which is commonly performed for reducing dead load moments and maintenance requirements, results in significant improvement in the seismic response of prestressed concrete girder bridges.

• Journal of the Korean Geosynthetics Society
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• v.19 no.1
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• pp.55-63
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• 2020

In this study, a scaled model test of the shaking table and a seismic analysis considering effective stresses were performed to reveal the dynamic behavior characteristics of box structures deep located in multi-layered soils upon seismic loading. The input seismic wave was operated below the ground using five seismic waves, including long period wave (Hachinohe), short period wave (Ofunato), artificial wave and real earthquakes that occurred in Gyeong-ju and Po-hang. As a result of model test and numerical analysis, the vertical displacement of box structures upon seismic loading was greater than that of horizontal direction, and it was confirmed that an increase of excess pore water pressure below the foundation ground caused a displacement. In addition, behavior of the ground and structures during artificial seismic wave appeared to be larger than real earthquake wave.

• Journal of the Korean GEO-environmental Society
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• v.18 no.5
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• pp.55-60
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• 2017

It is critical for Korea to make effective use of limited space as it has dense population and high traffic volume compared to its terrestrial area. To resolve this issue, diverse types of underground structures have increasingly been applied so far, and one of the most representative structures is double-deck tunnel. It has upper and lower roads separated by middle slab that shows dynamic behavior according to the vehicle and earthquake loads. In case of the characteristics of earthquake response, it is necessary to have exploratory study as it has high loads, complex working mechanism, and difficult theoretical approach. In order to understand the characteristics of earthquake response based on the supporting conditions of middle slab in double-deck tunnel, this study conducts indoor shaking table test with 3 test cases: (1) fix both brackets, (2) free and fix at each bracket and (3) free at both brackets for 2 seismic waves of artificial and Gyeongju earthquake. The result shows if the middle slab is free at both brackets, the acceleration response is reduced 41% for artificial earthquake and 60% for Gyeongju earthquake compared to the one with fix at both brackets.

• Journal of the Korea institute for structural maintenance and inspection
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• v.21 no.6
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• pp.59-66
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• 2017

In the case of fluid storage structure, hydrostatic pressure acts on the structure due to fluid surge during an earthquake. At this time, hydrodynamic pressure of the fluid charge not only by the strength of the earthquake but also by the sloshing height of the fluid. Factors affecting the change of load include the size, width and height of the fluid storage structure and height of fluid, time-history shape, etc. This paper wanted to identify the relationship between the earthquake shape and fluid free surface shape. The sloshing height measured the height of the fluid by applying earthquake to a tank whose width 500mm and comparison of the experiment and analysis. In addition, the shape of the fluid free surface was measured while varying the shape of earthquake and effective of the shape of earthquake of the fluid was analyzed.

• 한국정보통신설비학회:학술대회논문집
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• 2007.08a
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• pp.296-301
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• 2007

2007년 1월 20일 20시 56분경 오대산 부근에서 발생한 지진이 제주도를 제외한 전국에서 감지되어 우리 생활에 직접적인 영향을 끼치는 등 더 이상 우리나라도 지진에 안전한 나라가 아니라는 것이 입증되고 있으며, 정부에서도 자연재해대책법에 통신설비에 대한 내진설계 의무화 규정을 포함시켜 현재 시행을 눈앞에 두고 있는 시점에서 통신시설물에 대한 내진성능 평가와 내진대책 수립이 절실히 요구되고 있다. 따라서, 본 논문에서는 지진 발생시에 가장 민감하게 반웅하며 피해가 클 것으로 예상되는 통신 장치랙에 대하여 전력설비의 내진성능 검증에 사용되는 인공 지진파와 미국에서 측정한 실측 지진파를 진동대에 입력, 지진모사 실험을 실시하여 지진시 발생할 수 있는 통신장비의 기능 이상 유무를 확인하고 동적 거동 특성을 분석함으로써 장치랙이 보유한 내진성능을 도출하여 보았다. 이러한 지진모사 실험은 향후 통신 장치랙의 내진성능을 평가하는 기준을 수립하는데 중요한 기초자료로 활용될 것이라 판단된다.

• Journal of the Earthquake Engineering Society of Korea
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• v.5 no.2
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• pp.49-57
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• 2001

본 연구의 목적은 유사동적실험에 의한 섬유보강 원형 RC교각의 내진성능평가를 위한 연구로서 수원시에 위치한 내진교량인 하길교를 대상모델로 하였으며, 도로교 표준시방서의 내진설계규정이 적용되지 않은 비내진교각시험체 2본 및 내진성능향상을 위한 섬유보강시험 4본, 즉 총 6본에 대하여 유사동적실험을 수행하였다. 보강공법으로는 유리 탄소섬유 보강공법을 사용하였으며, 실험변수로는 입력지진동, 섬유고방유무로 하였다. 그리고 내진성능평가 방법은 입력 및 소산에너지, 변위 연성도가 분석되었다. 본 실험의 결과 유리 섬유로 보강된 비내진시험체의 변위연성도 KHC인공지진파에 대하여 7.7~9.0정도의 값으로 충분한 내진성능을 확보하고 있는 것으로 평가되었다.