• Structural Engineering and Mechanics
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• 제72권1호
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• pp.83-97
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• 2019

In this research, the vulnerability of some reinforced concrete frames with different stories are studied based on the Park-Ang Damage Index. The damages of the frames are investigated under various earthquakes with nonlinear dynamic analysis in IDARC software. By examining the most important characteristics of earthquake parameters, the damage index and vulnerability of these frames are investigated in this software. The intensity of Erias, velocity spectral intensity (VSI) and peak ground velocity (PGV) had the highest correlation, and root mean square of displacement ($D_{rms}$) had the lowest correlation coefficient among the parameters. Then, the particle swarm optimization (PSO) algorithm was used, and the sinusoidal waves were equivalent to the used earthquakes according to the most influential parameters above. The damage index equivalent to these waves is estimated using nonlinear dynamics analysis. The comparison between the damages caused by earthquakes and equivalent sinusoidal waves is done too. The generations of sinusoidal waves equivalent to different earthquakes are generalized in some reinforced concrete frames. The equivalent sinusoidal wave method was exact enough because the greatest difference between the results of the main and artificial accelerator damage index was about 5 percent. Also sinusoidal waves were more consistent with the damage indices of the structures compared to the earthquake parameters.

• 교통기술과정책
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• 제10권1호
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• pp.46-52
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• 2013

• 콘크리트학회지
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• 제9권1호
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• pp.29-35
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• 1997

• 한국측량학회지
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• 제23권3호
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• pp.239-249
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• 2005

우리나라는 비교적 지진의 안전지대라는 의식이 팽배하다. 따라서 지진이 발생할시의 대처 방안또한 미흡하다고 할 수 있다 그러나 해외의 사례를 살펴보면 지진에 대한 충분한 대비가 없다가 갑작스러운 재난으로 큰 피해를 입는 경우가 있다. 또한 우리나라의 지진 발생 사례를 조사해 본 결과 지진의 발발 횟수도 작지 않았다. 만약 이러한 지진이 서울과 같은 대도시에 일어난다면 그 피해는 매우 심각할 것이다. 그럼에도 불구하고 아직 우리나라는 지진에 대한 대책을 구체적으로 모색하는 것이 다른 나라에 비해 부족한 것이 현실이다. 본 연구에서는 지진에 대비해 GIS를 활용하여 다양한 요인으로 지진 위험도를 분석하였다. 지진 발생 시 위험 요인으로는 건물 도괴 위험도, 화재 위험도, 대피 위힘도 이렇게 세 가지 위험도에 대하여 분석하였으며 분석 방법은 다음과 같다. 먼저 지진에 의해 발생하는 건물 도괴, 화재, 대피의 어려움 등과 같은 대표적인 재해를 규정하였다. 다음으로 재해 위험 요소를 도출하기 위하여 토지이용 실태, 인구밀도, 건물유형, 도로구조 등을 정량화 하였고 이를 분석하여 위험도를 결정하였다. 또한 분석된 위험도를 기반으로 하여, 재해 발생의 최소화와 대비를 위한 개선 방안을 제시했으며, 활용의 예로 대피 시나리오를 구축하였다. 본 연구는 동대문구의 3개 동을 대상 지역으로 연구를 수행하였는데 향후 이러한 연구 방법을 활용하여 지역을 확대하며 지진에 대한 위험도를 사전에 도출한다면 지진이 발생하더라도 피해를 줄일 수 있으리라 기대된다.

• Structural Engineering and Mechanics
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• 제27권2호
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• pp.117-134
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• 2007

The force (load) reduction factor, R, which is one of the most important parameters in earthquake load calculation, is independent of the dimensions of the structure but is defined on the basis of the load bearing system of the structure as defined in earthquake codes. Significant damages and failures were experienced on prefabricated reinforced concrete structures during the last three major earthquakes in Turkey (Adana 1998, Kocaeli 1999, Duzce 1999) and the experts are still discussing the main reasons of those failures. Most of them agreed that they resulted mainly from the earthquake force reduction factor, R that is incorrectly selected during design processes, in addition to all other detailing errors. Thus this wide spread damages caused by the earthquake to prefabricated structures aroused suspicion about the correctness of the R coefficient recommended in the current Turkish Earthquake Codes (TEC - 98). In this study, an attempt was made for an approximate determination of R coefficient for widely utilized prefabricated structure types (single-floor single-span) with variable dimensions. According to the selecting variable dimensions, 140 sample frames were computed using pushover analysis. The force reduction factor R was calculated by load-displacement curves obtained pushover analysis for each frame. Then, formulated artificial neural network method was trained by using 107 of the 140 sample frames. For the training various algorithms were used. The method was applied and used for the prediction of the R rest 33 frames with about 92% accuracy. The paper also aims at proposing the authorities to change the R coefficient values predicted in TEC - 98 for prefabricated concrete structures.

• 대한원격탐사학회지
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• 제35권6_3호
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• pp.1221-1233
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• 2019

화산재 누적에 따라 발생할 수 있는 각 분야별 피해를 산정하는 것은 화산재 재해를 대비하는 측면에서 매우 중요하다. 본 연구에서는 기존 연구에서 제시된 공간정보 기반의 국내 화산재 피해 분야에 대하여 아소산 화산재 모의 확산 시나리오를 적용하여 각 분야에서 발생할 수 있는 화산재 피해의 정도를 나타냈다. 이를 위하여 기존의 사례 연구를 통하여 제시된 국내 화산재 피해 분야와 관련된 공간정보 자료를 수집하고 가공함으로써 화산재 피해 기반자료를 생성하였다. 수집된 두 개의 아소산 화산 모의 분화 시나리오를 활용하여 중첩분석을 통해 분야별 피해를 나타냈다. 그 결과 각 분화 시나리오에 대하여 162개, 134개 시군구에서 강회 피해 최소 기준인 0.01 mm 이상의 강회량에 따라 피해가 발생할 것으로 예상되었다. 가장 강회량이 많은 행정구역(시나리오 190805-강원, 경북; 시나리오 190811-춘천, 홍천)을 선정하여 발생 가능한 분야별 피해의 정도를 수집 가공한 공간정보 자료를 활용하여 서로 비교하였다.

• Earthquakes and Structures
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• 제3권2호
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• pp.117-140
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• 2012

The proposed research includes a comprehensive study on the seismic vulnerability assessment of typical building types, representative of the structural materials, the seismic codes and the construction techniques of Southern Europe. A damage database is created after the elaboration of the results of the observational data obtained from post-earthquake surveys carried out in the area struck by the September 7, 1999 Athens earthquake, a near field seismic event in an extended urban region. The observational database comprises 180.945 buildings which developed damage of varying degree, type and extent. The dataset is elaborated in order to gather useful information about the structural parameters influence on the seismic vulnerability and their correlation to the type and degree of building damages in near field earthquakes. The damage calibration of the observational data was based on label - damage provided by Earthquake Planning and Protection Organization (EPPO) in Greece and referred to the qualitative characterization for the recording of damage in post-earthquake surveys. Important conclusions are drawn on the parameters that influence the seismic response based on the wide homogeneous database which adds to the reliability of the collected information and reduces the scatter on the produced results.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2006년도 학술발표회 논문집
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• pp.56-63
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• 2006

Facilities of 76skV Substation(S/S) play an important role in electric power supply grids. Various power facilities of 765kV S/S might be damaged enormously if a strong earthquake occurs. In an effort to mitigate possible earthquake disasters, KEPRI (Korea Electric Power Research Institute) set forth plans to verify seismic safety of the facilities of 765kV S/S. To accomplish the task, an earthquake monitoring systems is constructed at four 765kV S/S sites(Shin-AnSung, Shin-TaeBaek, Shin-SeoSan and Shin-GaPyung). Data from these earthquake monitoring stations are being transmitted via satellite communication. Currently, KEPRI is operating an earthquake monitoring system in freefield of Shin-SeoSan S/S (NSS) tentatively, Also, the data from NSS is preliminarily analyzed using the horizontal to vertical (H/V) spectrum ratio method. The method of H/V spectrum ratio has been used to infer site amplification without previous knowledge of near surface geology. The results of data analysis shorts good S/N ratio and amplification of 20-25 Hz by site effect. In the near future, the accumulated data is expected to provide a basis for assessing and predicting any damages to integrity of 765kV S/S facilities by earthquakes.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2002년도 추계 학술발표회 논문집
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• pp.173-180
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• 2002

This paper presents a signal processing procedure to detect damage locations of frame structures by using continuous wavelet transform. Morlet wavelet is used as a mother wavelet in wavelet transform. Wavelet transform has the characteristics that allows the use of long time intervals at more precise low-frequency information, and shorter regions at high-frequency information. By this wavelet transform characteristics, Morlet wavelet may be used to identify the locations of damages in the structures. The numerical case studies show that this method can be applied to detect the damage location under a controlled sweeping load.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2003년도 춘계 학술발표회논문집
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• pp.174-181
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• 2003

The groundborne vibration from moving train loads in tunnels could cause damages on structures and make people uneasy. With an aim at developing basis for effective screening measures, this paper attempts to study the characteristics of propagation and attenuation of groundborne vibration from moving train loads in tunnels considering the effect of joints. The wave propagation problem is modeled by a commercial code FLAC and the results are compared to those from using a finite-element-based code DIANA. It is shown that the groundborne vibration is affected significantly by the location and direction of joints.