• Journal of the Earthquake Engineering Society of Korea
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• v.15 no.4
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• pp.45-54
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• 2011

A simple model for reinforced concrete shear walls with boundary elements is proposed, which is a macro-model composed of spring elements representing flexure and shear behaviors. The flexural behaviour is represented by vertical springs at the wall ends, where the moment strength and rotational capacity of the wall are based on section analysis. The shear behaviour is represented by a horizontal spring at the wall center, where the key parameters for the shear behavior are based on the flexural behaviour since the shear walls with boundary elements are governed by the flexure. The proposed model was prepared with the results of hysteretic tests of the shear walls, and then the reliability of the hysteretic rule and variables was investigated by nonlinear dynamic analyses. Using parametric study with nonlinear dynamic analyses, the effect of the variables on demand and capacity, which are major parameters in seismic performance evaluation, are investigated. Results show that the measured and calculated shear forces versus the shear distortion relationships are slightly different, but the global response is well simulated. Furthermore, the demand and capacity are also changed in a similar way to the change in the major parameters so that the proposed model may be appropriate for reinforced concrete shear walls with boundary elements.

• Journal of the Korean earth science society
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• v.24 no.4
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• pp.361-368
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• 2003

We have investigated the electric resistivity structure of the fault zone located in the Hongseong area where a big earthquake with M 5.0 occurred in 1978. Usually, Electric and Electromagnetic methods are broadly operated in the field of engineering works since these methods are effective to understand the distribution of geological weak zones - fault or fracture zones. We have conducted the dipole-dipole array resistivity method and MT(magnetotelluric) method and interpreted the resistivity distribution of the fault zone with the aid of various inversion methods. An MT survey was performed at 18 points along a 2.9 km survey line perpendicular to the fault line and a magnetic dipole source was used to enhance the S/N ratio in the high frequency. A Electric dipole-dipole array resistivity survey with the dipole length of 50 meters was carried out perpendicular to the fault. In view of two survey results, the fault marks the boundary between two opposite resistivity structures, especially the low resistivity zone is exhibited deeply through the prospective fault line. The result that the low resistivity zone is located at the center of the fault zone corresponds with the fact that the fault zone of the Hongseong area is active. We expect these results to provide basic information about the physical properties of fault zones in Korea.

• Journal of The Geomorphological Association of Korea
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• v.19 no.3
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• pp.143-151
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• 2012

The tsunami disasters and tectonic movements derived from mega-earthquake(M 9.0) which occured in the sea floor of the Pacific side of northeast Japan in March, 2011 were investigated. Landward invasion limit of the tsunami was 4.0km from the present coastline in Sendai coastal plain. It was observed that sandy deposit was dristributed largely in coastward part and muddy deposit was distributed largely in landward part. The ratios of distribution distances of the above two deposits were, respectively, 60~75% and 25~40% of the whole invasion distance of the 2011 tsunami. The ratios of the above distribution distances of tsunami deposits could be used to estimate landward invasion distances of the past maga-tsunamies(e.g. '2,000year B.P. Mega-Tsunami' and 'Jogan Tsunami' etc.) in Sendai coastal plain. The mega-scale tsunami disasters were caused by the low and flat geomorphic condition in the Sendai coastal plain and the increasing effect of tsunami height affected by narrow inlet condition of the so-called Ria's coast in the Sanriku coastal area respectively. Tectonic subsidences caused by the mega-earthquake in march, 2011 were observed in many areas of Ishinomaki, Ogawa, Ogachi and Onagawa coasts in northeast Japan. The displacements of tectonic subsidence were between 0.5 meters and 1.0 meters.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.1C
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• pp.63-74
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• 2008

Site response analyses were performed based on equivalent linear technique using the local geologic and dynamic site characteristics, which include soil profiles, shear wave velocity profiles and depth to bedrock for 125 sites collected in Korean Peninsula. From the results of site response analyses, 2-parameters site classification system based on the combination of mean shear wave velocity of soil and depth to bedrock was newly recommended for regions of shallow bedrock depth in Korea. First, as the borders of bedrock depth (H) for site classification were determined as 10m and 20m, the soil sites were divided into 3 classes as $H_1$, $H_2$ and $H_3$ sites. And then, the 3 site classes were subdivided into 7 classes based on the mean shear wave velocity of soil ($V_{s,soil}$). The feasibility of new site classification system was verified and the representative site coefficients ($F_a$ and $F_v$) and design response spectrum were suggested by analyzing uniform trend and dispersion of site coefficients for each site class. The suggested site coefficients and the regression curves present the nonlinear characteristics of soils according to the change of rock outcrop acceleration with uniform trend effectively. From the comparison between the mean values of response spectrum which was acquired from the site response analysis and the suggested design response spectrum, there was a little difference in some of site classes and it was verified to adjust the integration interval to make it more suitable for the site condition in Korea.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2008.11a
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• pp.21-26
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• 2008

We investigate the various factors such as earthquake, fire, flood and deterioration factors such as carbonation, salt attack, freezing thawing, alkali-aggregate reaction effects on the school facilities. As the consequence of this study we can see that there are very relative relation between deterioration factors and disaster factors. It is the aim of this study to investigate the site analysis damaged by disaster and deterioration factors of school facilities.

• 한국방재학회:학술대회논문집
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• 2007.02a
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• pp.383-386
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• 2007

The present study aims to document the run-up height, losses of human lives and property damage due to the tsunami occurred on December 26, 2004 in Andaman and Nicobar Islands, India. These Islands were severely devastated by the tsunami. Approximately 1,925 people were lost their lives and 5,555 people were reported missing. A field survey carried out at 26 locations indicates that the passenger jetty of Little Andaman area recorded the highest run-up height of 17.3m and the Chidiyatopu area had the greatest inundation of 500m from the coastline.

• 한국공간정보시스템학회:학술대회논문집
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• 2007.06a
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• pp.413-423
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• 2007

우리나라의 자연재해는 기상학적 자연현상에 의해 주로 발생되고 있으며 그 발생원인은 태풍, 호우, 폭풍, 폭풍우, 재설, 폭풍성 우박, 해일 및 기타(낙뢰, 돌풍, 설해, 결빙, 지진 등을 포함)로 구분되며 이중 발생빈도가 가장 높은 것은 강우에 의한 재해로 전체 재해발생 원인 중 약 80%로 대부분을 차지하고 있다. 특히 사면붕괴와 관련된 자연재해(산사태, 옹벽붕괴, 매몰 등)는 최근 국지성 집중호우를 포함하여 호우의 집중 강도가 높아지는 등 기상학적 원인에 의해 매년 발생하고 있다. 따라서 우리나라에서 발생되는 자연재해와 관련한 사면붕괴의 특성을 강우특성에 따라 조사 분석할 필요가 있으며 이에 적합한 대책들이 더욱 필요하다. 이 연구에서는 산사태 유발인자와 강우조건을 고려하여 산사태 잠재가능성을 평가하고 산사태 취약지역을 분석하여 지역적인 강우특성을 고려한 산사태 가능성을 평가하였다.

• 한국공간정보시스템학회:학술대회논문집
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• 2007.06a
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• pp.212-216
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• 2007

본 연구의 목적은 도시 지역에서 지진 발생시 중요한 대피로 역할을 하는 도로의 위험평가요소를 분석하고 데이터베이스(Database, DB)를 구축하는데 있다. 현재 우리나라는 도로의 체계적인 유지관리를 위해 도로관리통합시스템이 개발되어 있으나, 이는 도로대장전산화, 포장관리시스템, 교랑관리시스템, 도로절개면유지관리시스템 등에 한정되어 있다. 다시 말해서 재난 시 사람들이 신변의 안전을 확보할 수 있는 대피나 구급을 위한 통로로써의 도로에 대한 이해가 부족한 실정이다. 따라서 본 연구에서는 선행연구의 분석을 토대로 방재관점의 도로관리를 위한 항목들을 자연환경, 시회환경, 도로 및 시설물, 유발요인 등으로 제안하고, 서울대학교 부근을 대상지역으로 하여 이들 요인을 DB화하였다. 이는 도로와 주변 환경 등을 동시에 고려하여 재난 발생 시 대피와 구조 활동을 위한 방재계획은 물론, 지역별 위험도평가 및 재해위험도작성에 기초 자료로 이용될 것으로 기대된다. 그러나 본 연구에서는 기구축된 GIS 자료가 아닌 현장 조사를 바탕으로 구축된 DB로, 방재관점의 통합된 DB의 필요성을 제시하는데 그 의미가 있을 것이다.

• Proceedings of the KAIS Fall Conference
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• 2009.12a
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• pp.339-341
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• 2009

연안역에 대한 관심이 고조되면서 연안역을 따라 많은 산업화와 관광권화가 진행되고 있으나 안전시설에 대한 무관심으로 인해 많은 인적 및 물적 피해가 속출하고 있다. 충청권 연안역이 가지고 있는 지역적(관광, 산업, 방조제 등) 및 자연적(조수, 해일, 지진, 해양기름유출, 해안습지, 태풍 등) 특성을 고려한 연안역 안전시설을 개발하고자 연구를 수행하고 있다. 선행연구로 서해안 연안역 현장조사를 통한 안전시설물의 설치 현황을 살펴보고 이를 분석하였으며, 이를 통해 연안역 안전시설의 성능 및 설계기준, 건설재료 등에 대한 연구를 기획하였다. 연구과제의 최종 수행결과물로서 제시될 해안 안전 시설물 계획 설계 시공 유지관리에 대한 개발추진계획을 제시한다.

• Proceedings of the Safety Management and Science Conference
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• 2009.04a
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• pp.167-175
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• 2009

전 세계적으로 이상 고온, 폭우, 가뭄, 지진, 해일 등이 빈번하게 발생하고 있다. 그 피해 규모도 앞으로 계속 커질 전망이다. 경제활동의 주체인 기업이 이러한 자연 재해로 인하여 지속적이고 안정적으로 운영되지 못하게 된다면 이는 기업자체는 물론 치 열한 글로벌 경쟁체제 속에서 국가경쟁력향상에 상당한 타격을 줄 수 있다. 하지만 우리나라의 기업은 선진국에 비해 상대적으로 자연재해 발생 시 체계적인 방재시스템을 구축하지 못하고 있다. 본 논문에서는 자연재해저감기술 개발의 필요성과 선진국가의 사례들을 통한 우리나라의 자연재해저감기술이 나아갈 방향성을 모색하고자 한다.