• Journal of the Computational Structural Engineering Institute of Korea
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• v.32 no.3
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• pp.149-154
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• 2019

The structural system of domestic high-rise apartments can be divided into two parts; the core wall system, which is composed of walls concentrated in the center and the shear wall system, which comprises a great number of walls distributed in the plan. In order to analyze the lateral behavior of each system, buildings with typical domestic high-rise apartment plans were selected and nonlinear static analysis was performed to investigate the their collapse mechanism. From the force-displacement relation derived from nonlinear static analysis, response modification factor was evaluated by calculating the overstrengh and ductility factor, which are important in the seismic response. The ductility of core wall system is small, but as it is governed by wind load, its overstrength is greatly estimated, and its response modification factor is calculated by the overstrengh factor. Due to a large number of walls, shear wall system has a large ductility, making the response modification factor considerably large.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.350-350
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• 2016

댐 및 저수지 시설물의 붕괴에 대비하기 위한 댐 붕괴 비상대처계획 수립은 대규모 인명 또는 재산의 피해를 예방하기 위한 중요한 비구조적 대책중의 하나이다. 특히 대규모 댐붕괴로 인한 재난 발생시 국민의 생명과 재산 피해를 최소화하기 위해 댐 시설물의 관리주체 및 유관기관은 발생가능한 비상상황을 미리 예측하고, 대응조치를 신속하고 효율적으로 집행해야 한다. 댐 붕괴 비상대처계획 수립을 위해 가장 중요한 사항은 댐 붕괴 위험도를 파악하고, 발생가능한 여러 시나리오에 따른 댐 하류부의 피해정도를 예측하는 일이다. 댐 붕괴 비상대처계획 시 작성되는 홍수범람 지도는 댐 붕괴사고가 발생했을 때 주민대피계획 및 위험지역 교통통제, 응급의료활동 및 생필품 공급 등, 비상대처계획 수립을 위한 가장 기본적인 자료가 된다. 현재 우리나라는 댐 붕괴 비상대처계획 수립을 위해 1차원 또는 2차원 수리해석 모형을 이용하여 홍수범람지도를 작성하고 있다. 전체적인 비상대처 계획도 작성을 위해 댐 붕괴로 인한 홍수파 해석이 가능한 1차원 수리해석 모형을 주로 이용하지만, 홍수파가 전파되는 하류부의 지형학적 특성상 2차원 해석이 필요한 지역에 대해 2차원 수리해석 모형을 이용하여 추가의 검토가 이루어지고 있다. 본 연구에서는 비상대처계획시 동시에 활용되는 1차원 수리해석 모형과 2차원 수리해석 모형의 특성을 각각 분석하고, 시범지역의 가상 댐 붕괴사상에 대해 적용함으로써, 각 모형의 장단점과 적용성에 대한 비교 검토 연구를 수행하였다. 낙동강유역내 위치한 다목적댐에 대해 1차원 및 2차원 붕괴모의를 실시하였으며, 여러 시나리오에 대해 1차원 모형과 2차원 모형 각각에 대해 동일하게 적용함으로써 두 모형의 모의 결과에 대한 비교 분석을 실시하였다. 본 연구를 통해 비상 대처계획 수립을 위한 홍수범람지도 작성 시 1차원 모형과 2차원 모형의 장점을 각각 반영할 수 있도록 홍수범람지도를 효율적이고 정확하게 작성하기 위한 제언을 제시하고자 하였다.

• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.214-214
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• 2017

우리나라는 도시화 및 산업화로 도시지역의 대부분이 불투수층으로 변화하였으며, 국지성 호우의증가로 홍수 저감시설의 방어능력이 취약한 실정이다. 따라서 홍수방어 개선을 위한 여러 방안들이 이루어지고 있으며, 그 중 저류지는 도시지역에서 유역 하류의 홍수피해 저감 및 흐름을 지체시켜 유출률을 감소시키는 시설물로 홍수 저감을 위한 시설물로 가장 많이 사용되고 있다. 저류지는 큰 규모일수록 유역의 하류지역에 설치할 경우 가장 큰 유출저감효과를 가지는 것으로 알려져 있다. 하지만 저류지의 위치를 유역의 하류가 아닌 상류지역에 설치할 경우에는 단기간 강우의 시간적 분포가 강우 초기에 집중될 경우 저류지의 허용용량이 초기에 도달하게 되어 추가적인 강우가 발생할 경우 본래의 역할을 하지 못하는 경우가 빈번하게 발생하고 있다. 그러므로 다양한 강우강도 및 시간적 분포를 고려하여 유역의 특성 및 저류지의 설치위치에 따른 관계를 분석할 필요가 있다. 본 연구에서는 도시화, 산업화 인구집중으로 인해 동일규모의 강우에서도 우수유출이 증대되고 있는 도시지역에서 원활한 내수배제를 위해 기존의 우수관거를 연계한 저류시스템인 간선저류지 개념을 적용하여 강우강도 및 시간적 분포에 따른 간선저류지의 관련매개변수를 분석하였다. 대상유역은 세장형, 집중형, 중앙형의 3가지 형상의 가상유역으로 선정하여 다양한 지속기간의 강우량을 적용하였으며, 간선저류지의 설치위치는 전체 유역면적에 대한 저류지 상류부 면적의 비(저류지 상류부 면적비, DUAR ; Dimensionless Upstream Area Ratio)를 20%, 40%, 60%, 80%로 변화시키면서 강우의 시간적 분포에 따른 간선저류지의 매개변수 분석에 관한 연구를 진행하였다.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.36 no.4
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• pp.13-22
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• 2020

Recent abnormal climate has increased the frequent of heavy rains and floods, and over 100 people have been killed in the last decade caused by these. In the midst of severe flood disasters, safety education to learn how to respond and evacuate them has become important. The purpose of this study was to analyze the needs and effective education types for the flood disaster school safety education. This study shows Analysis the current state of school safety education based on the 7 standards of school safety education, especially in disaster safety categories through the survey of secondary school teachers and students. And a desirable form of flood safety education was derived by analysis of awareness of flood disaster safety education and their educational needs. More than 70% of teachers and students hoped for a experience-based flood disaster safety education, they wanted to learn once a year, one hour from a safety education specialist in experience facilities. As for the contents of the training, they wanted to experience evacuation in the event of flood disaster, and also wanted education related to survival swimming. The most necessary thing for the establishment of experience-based disaster safety education was the expansion of experience facilities.

• Korean Journal of Remote Sensing
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• v.37 no.3
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• pp.591-601
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• 2021

As the domestic chemical industry continues to develop, handling and transportation of chemicals increases every year. Road freight in Korea accounts for more than 90%, and most of the chemical transportation is done through roads. These chemical vehicles can lead to major accidents if accidents occur. Transportation vehicles are likely to cause water pollution and soil pollution, which are factors of environmental damage, as well as traffic accidents that are the primary damage. In this work, we write a scenario for hydrogen chloride gas leakage by setting Banpo IC and Seocho IC sections as research areas, and use the ALOHA program to measure the predicted distance and analyze the time when hydrogen chloride gas reached according to the distance. In addition, risk assessment using population density was carried out for areas of damage caused by time using GIS. This suggests the need for prevention and countermeasures in areas of damage.

• Journal of the Korean Society of Industry Convergence
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• v.25 no.5
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• pp.811-816
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• 2022

Even though continuous management and supervision of reinforcement of policies to safeguard accidents at workplace and work sites were implemented. Accident prevention activities such as inspection and diagnosis are urgently required to induce a preliminary investigation to identify the risk factors for each type of work, before the work task to eliminate risks at the worksites. Since safety inspections at work sites were generally conducted through visual inspections, the results of safety inspections may vary depending on the findings and proficiency of the safety officers. The results of those inspections may have loopholes to prevent potential accidents at work. Therefore, the purpose of this study was to develop a risk identification checklist that can effectively perform safety inspections to prevent accidents at work sites. This study initially analyzed the previously developed accident checklist to identify current complications and issues in safety checklists. Based on the findings of major industrial accidents over the past three years, the relationship between accident, workplace, and work type were analyzed refereeing the safety inspection standards. A risk recognition-checklist was developed to provide basic data on identifying risk factors, and inspection guidance at work sites. To prepare for potential accidents by identifying and taking countermeasures to mitigate the high risk and serious accidents at sites by the guidelines of the checklist. The developed inspection checklist has been practically used by experts at work sites to perform safety inspections, and it has been verified its suitability, and feasibility, to prevent or mitigate workplace accidents, including securing the safety and health of field workers. The role of the developed safety checklist has been considered effective at worksites.

• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.4
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• pp.37-45
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• 2021

This paper is a basic study to evaluate the possibility of earthquake-resistant reinforcement by reinforcing engineered cementitious composite in masonry members. In order to examine the performance according to the fiber mixing rate of the engineered cementitious composite, a test specimen was prepared according to the formulation design, and flow ability, compressive strength, flexural strength, length change rate, and direct tensile strain were measured. In addition, non-reinforced masonry members, masonry members reinforced with engineered cementitious composite, and masonry members in which glass fibers and wire mesh were separately reinforced with engineered cementitious composites were manufactured, and flexural strength and maximum displacement were measured. All specimens reinforced with engineered cementitious composite showed more than 16 times the effect of maximal strength compared to that of no reinforcement, and as a result of examining the crack shape, the energy dissipation ability was excellent, confirming the possibility of seismic reinforcement.

• Journal of the Korean Society of Safety
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• v.37 no.6
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• pp.89-95
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• 2022

A method for measuring the length and slope of a temporary structure using an unmanned aerial vehicle (UAV) and 3D modeling method is proposed. The actual length and slope of the vertical member of the specimen were measured and compared with the measured values obtained by the proposed method for the specimens with and without the vertical protection net installed. Based on the result of measuring the length of the temporary structure specimen using the UAV and 3D modeling method, the measured value showed an error of 0.87% when compared to the actual length in the specimen without the vertical protection net installed. In addition, the error of the slope was 0.63°. It was thought that the proposed method could be usable for the purpose of finding parts in wrong installation state on the temporary structure and informing the manager in charge. However, in the case of the specimen with the vertical protection net, the measurement showed a 1.46% error in length and 2.77° difference in slope. Therefore, if a vertical protection net is to be installed in a temporary structure, the measurement accuracy should be improved by utilizing an image processing method, etc.

• Journal of the Korean Society of Safety
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• v.37 no.4
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• pp.36-43
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• 2022

Generally, in construction sites, the pipe support installation workers often use support pins of 9~10 mm which are much smaller than the safety standard sizes for work convenience. Although the safety certification standard thickness of the support pins is 11 mm, and the supervisors are often indifferent to this. Hence, products with far lower performance than the pipe support safety certification value of 40,000 N, which is applied in the supporting post-structural review, are used. Accordingly, this acts as a factor causing collapse accidents in the process of pouring concrete at the construction site. Therefore, this study performed compression experiments on new and reused pipe supports to determine how the thickness of the support pins affects the structural compression performance of the pipe support by considering the thickness of the support pins as a critical variable among various factors affecting the pipe support performance. In the course of the study, the compression test of the pipe support (V2, V4) for the new products showed that only 14 (58.3%) of the total 24 samples satisfied the safety certification standard value of 40,000 N, which indicates that more thorough quality control is required in the manufacturing process. Additionally, comparing the thickness of the support pins and their fracture shape shows that the pipes with support length of 4.0 m or longer are much more affected by the buckling of the entire length than the thickness of the support pins. Of the several factors affecting the performance of reused pipe supports, it was found that, similar to the new products, the use of support pins, with thickness of 12 mm rather than 11 mm, can satisfy the safety certification value more appropriately. Therefore, regardless of the state of usage, it could be concluded that it is necessary to use 12 mm products, whose thickness is larger than that of the safety certification standard value of 11 mm, to improve the performance of the pipe supports.

• Journal of the Earthquake Engineering Society of Korea
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• v.27 no.5
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• pp.221-230
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• 2023

This study proposes a methodology for assessing seismic liquefaction hazard by implementing high-resolution three-dimensional (3D) ground models with high-density/high-precision site investigation data acquired in an area of interest, which would be linked to geotechnical numerical analysis tools. It is possible to estimate the vulnerability of earthquake-induced geotechnical phenomena (ground motion amplification, liquefaction, landslide, etc.) and their triggering complex disasters across an area for urban development with several stages of high-density datasets. In this study, the spatial-ground models for city development were built with a 3D high-precision grid of 5 m × 5 m × 1 m by applying geostatistic methods. Finally, after comparing each prediction error, the geotechnical model from the Gaussian sequential simulation is selected to assess earthquake-induced geotechnical hazards. In particular, with seven independent input earthquake motions, liquefaction analysis with finite element analyses and hazard mappings with LPI and LSN are performed reliably based on the spatial geotechnical models in the study area. Furthermore, various phenomena and parameters, including settlement in the city planning area, are assessed in terms of geotechnical vulnerability also based on the high-resolution spatial-ground modeling. This case study on the high-precision 3D ground model-based zonations in the area of interest verifies the usefulness in assessing spatially earthquake-induced hazards and geotechnical vulnerability and their decision-making support.