• 한국지진공학회논문집
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• 제20권7_spc호
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• pp.561-567
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• 2016

After the Gyeong-ju 9.12 earthquake, we found the necessity of seismic design of nonstructural element is important to reduce damages in view of properties and economic losses. This study focused on the investigation of damages including both properties and human beings. It was found that most of the damages are leaking of water pipe line, rupture of glasses, spalling of roof finishing, cracks of building, and falling from roof. It was also found that the seismic design force of nonstructural elements is taking account into the natural periods, amplification factors, response modification factors to forsee inelastic behaviors. From this studies, it is recommended that more studies are necessary on the seismic design force of nonstructural element.

• 한국지진공학회논문집
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• 제20권7_spc호
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• pp.495-502
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• 2016

In this paper, time and frequency domain characteristics of Gyeong-ju earthquakes were investigated, and nonlinear time history analyses were conducted for bi-linear hysteretic structures excited by short-duration ground accelerations. Previous studies showed that larger inelastic displacements than the peak displacement of the corresponding elastic system were observed especially for the structures with structural period shorter than 0.3s, and the similar results could be obtained when long-duration ground accelerations were used as excitation loads. For the short-duration earthquakes, however, the inelastic displacements were not so large and almost identical to the peak elastic displacements.

• 한국지진공학회논문집
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• 제20권7_spc호
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• pp.503-508
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• 2016

In this study, effectiveness of seismic retrofitting methods using passive damping devices was investigated through numerical analyses of short-period structures under earthquakes which have short-duration and high-frequency impulse characteristics similar to Geyongju earthquakes. Displacement spectra of elastic systems and ductility demand of inelastic systems were evaluated by increasing viscous or friction damping. The damping devices could reduce responses of the structures with shorter structural period than 0.2s. The earthquakes similar to impulse load did not induce the responses of the structures with longer period than 0.4s, and the effects of the damping devices which generates damping forces proportional to structural responses became insignificant.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 1998년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Spring 1998
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• pp.407-412
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• 1998

Amplification factor spectrum, using the observed strong ground motions database, has been obtained and compared with Standard Response Spectrum, which were suggested by US NRC. The observed ground motions from the Yongwol and the Kyoungju Earthquake, respectively, which are suppose to represent domestic seismotectonic characteristics such as seismic source, attenuation, and site effect, are used for the analysis of amplification factor spectrum. Amplification factors have been calculated by comparing the observed peak ground motions with results from responses to the observed horizontal and vertical ground motions. The comparison shows that the amplification factors resultant from this study exceeds those of Standard Response Spectum at relatively higher frequencies. The results suggest that the characteristics of the seismic strong ground motion, which are supposed to represent the domestic seismotectonic characteristics, differs from those of Standard Response Spectrum, especially at hither frequencies

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 1999년도 춘계 학술발표회 논문집 Proceedings of EESK Conference-Spring
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• pp.57-60
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• 1999

Amplification factor spectrum using the observed strong ground motions database in the Korean Peninsula has been obtained and compared with Standard Rpectrum which wa suggested by United States Nuclear Regulatory Committee. The observed ground motions from the Yongwol and the Kyoungju Earthquakes respectively which are supposed to represent domestic seismotectonic characteristics such as seismic source attenuation of the propagation meium and site specific effect are used for the analysis of amplification factor spectrum,. The database are slightly different from the those of the second study. Amplification factors have been calculated by comparing the observed peak ground motions with results from responses to the observed horizontal na vertical ground motions. The comparison have shown that the amplification factors resultant from this study exceeds those of Standard Response Spectrum The results suggest that the characteristics of seismic strong ground motion which are supposed to represent the domestic seismotectonic characteristics differs from those of Standard Response Spectrum especially at higher frequencies. The results from the 2nd study are similar to those of 1st analysis.

• 한국지진공학회논문집
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• 제24권2호
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• pp.59-65
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• 2020

The empirical Green's function method is applied to the foreshock and the mainshock of the 2016 Gyeongju earthquake to simulate strong ground motions of the mainshock and scenario earthquake at seismic stations of seven metropolises in South Korea, respectively. To identify the applicability of the method in advance, the mainshock is simulated, assuming the foreshock as the empirical Green's function. As a result of the simulation, the overall shape, the amplitude of PGA, and the duration and response spectra of the simulated seismic waveforms are similar with those of the observed seismic waveforms. Based on this result, a scenario earthquake on the causative fault of Gyeongju earthquake with a moment magnitude 6.5 is simulated, assuming that the mainshock serves as the empirical Green's function. As a result, the amplitude of PGA and the duration of simulated seismic waveforms are significantly increased and extended, and the spectral amplitude of the low frequency band is relatively increased compared with that of the high frequency band. If the empirical Green's function method is applied to several recent well-recorded moderate earthquakes, the simulated seismic waveforms can be used as not only input data for developing ground motion prediction equations, but also input data for creating the design response spectra of major facilities in South Korea.

• 한국지진공학회논문집
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• 제25권6호
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• pp.233-240
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• 2021

The stochastic method is applied to simulate strong ground motions at seismic stations of seven metropolises in South Korea, creating an earthquake scenario based on the causative fault of the 2016 Gyeongju earthquake. Input parameters are established according to what has been revealed so far for the causative fault of the Gyeongju earthquake, while the ratio of differences in response spectra between observed and simulated strong ground motions is assumed to be an adjustment factor. The calculations confirm the applicability and reproducibility of strong ground motion simulations based on the relatively small bias in response spectra between observed and simulated strong ground motions. Based on this result, strong ground motions by a scenario earthquake on the causative fault of the Gyeongju earthquake with moment magnitude 6.5 are simulated, assuming that the ratios of its fault length to width are 2:1, 3:1, and 4:1. The results are similar to those of the empirical Green's function method. Although actual site response factors of seismic stations should be supplemented later, the simulated strong ground motions can be used as input data for developing ground motion prediction equations and input data for calculating the design response spectra of major facilities in South Korea.

• 한국컴퓨터정보학회:학술대회논문집
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• 한국컴퓨터정보학회 2021년도 제64차 하계학술대회논문집 29권2호
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• pp.61-64
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• 2021

2016, 2017년 경주와 포항에서 발생한 규모 5.4 이상의 지진 당시 건물에 많은 피해가 속출함에 따라 지진 발생 시 건물 안전에 관한 관심이 증가하고 있다. 이러한 이유로 지진 등의 재난 상황 시 건물의 위험도를 신속하게 판단할 수 있는 방법론이 필요한 실정이다. 본 논문에서는 지진 등의 재난 상황 시 건물 안전에 위협이 될 수 있는 건물 기울기에 대한 위험도를 자이로 센서 데이터에 기반해 산출하는 시스템을 제안한다. 본 논문에서는건물 기울어짐 데이터를 확보함에 어려움이 있어 모의 거동 환경을 구축하여 데이터를 수집 및 분석하였다. 제안된 시스템은 자이로 센서로부터 수집된 실시간 기울기 데이터를 Mean Filter를 통해 데이터 평탄화 및 선형화를 수행 후 머신러닝 기법중 하나인 선형 회귀 알고리즘을 적용해 건물 기울기를 추정한다. 이후 국토교통부에서 고시한 건물 기울기 위험도 산출표를 바탕으로 측정된 기울기의 위험도를 산출한다. 해당 시스템은 실제 지진 등의 재난 발생 시 실시간 건물 기울기 위험 판단을 통해 신속한 재난 의사 결정에 도움이 될 것으로 기대된다.

• 한국지반환경공학회 논문집
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• 제18권5호
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• pp.55-60
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• 2017

우리나라는 제한된 국토 면적에 비해 인구 밀도가 높고 그에 따른 교통량 증가로 인한 효율적인 공간 이용의 필요성이 시급하다. 이를 위해 여러 가지 지하구조물의 건설이 증가하고 있으며 그 대표적인 것이 복층터널이다. 복층터널 내에는 상, 하부차도를 구분하는 중간슬래브가 있고 이러한 중간슬래브는 차량하중 및 지진하중에 의한 동적거동을 보이게 된다. 특히 지진에 의한 응답특성은 하중의 크기도 클뿐더러 작용 메커니즘이 매우 복잡하고 이론적인 접근이 쉽지 않아 실험적 연구가 필수적이다. 따라서 본 연구에서는 복층터널 중간슬래브 지지조건에 따른 지진 시 응답특성을 파악하기 위하여 실내 진동대 시험을 수행하였다. 이를 위하여 중간슬래브의 양쪽 지지단을 모두 고정, 한쪽 탄성지지, 양쪽 탄성지지의 3가지 경우로 나누어 각각 인공지진파 및 경주실지진파의 2가지 지진파를 적용하여 시험을 수행하였다. 그 결과, 양단 고정 조건에 비하여 양단 탄성지지 조건일 경우 가속도 응답이 인공지진파에서 최대 약 41%, 경주실지진파에서 최대 약 60% 감소함을 확인하였다.

• 한국조경학회지
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• 제45권4호
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• pp.62-70
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• 2017

2016년 9월 12일 경상북도 경주시역에서 발생한 규모 5.8의 지진은 한국이 더 이상 지진으로부터 안전한 지역이 아님을 전 국민에게 확실하게 인지하게 하였다. 도시 녹지는 특성상 양호한 지진 대피 기능을 지니고 있는 도시 내 중요한 지진 대피 장소이다. 그러나 공원녹지는 지진 대피 적절성에 대한 연구의 부족으로 지진 발생 후 피난 장소로 활용되지 못하고 있는 경우가 많다. 본 연구는 도시 공원이 지진 대피 장소로써의 적절성을 평가하기 위한 지표를 개발하기 위해 델파이 기법을 활용하여 3차에 걸쳐 조사를 실시하였다. 조사 결과에 대한 평균(M), 표준편차(SD), 합의도, 수렴도, 내용타당도 지수(CVR) 등을 분석하여 총 37개 지표 중 10개의 지표들을 기준에 부합하지 않기 때문에 제거하였고, 최종 27개의 지표가 선정되었다. 최종 연구 결과, 공원녹지의 지진 대피 적절성 평가에 대한 안전성과 접근성, 서비스 효과성은 각각 8개, 6개, 13개의 평가지표가 선정되었다.