• Proceedings of the Korea Institute of Fire Science and Engineering Conference
• /
• 2005.11a
• /
• pp.201-207
• /
• 2005

• 한국방재학회:학술대회논문집
• /
• 2010.02a
• /
• pp.80-80
• /
• 2010

연안역에 대한 사회적 관심이 높아지면서 산업화 및 관광권역화가 급속하게 진행되고 있다. 그러나 연안역에서 발생하는 잇따른 안전사고로 인해 인적, 물적 피해가 증가하고 있는 실정이다. 피해사례를 분석한 결과, 대다수 사고가 안전시설물이 설치되어 있지 않거나 안전시설물의 시인성이 확보되지 않아 발생하는 것으로 나타났다. 이에 따라 본 연구에서는 연안역 안전 시설물의 시인성 확보 필요성을 제시한다.

• 한국방재학회:학술대회논문집
• /
• 2008.02a
• /
• pp.49-52
• /
• 2008

The design strength of panel zones, which was based on Krawinkler model, was investigated by comparing it with existing test and FEM results. The design strength overestimates of the strength of panel zones with thick column flange while it matches well with the strength of panel zones with thin column flange. More extensive studies are needed to develop a mathematical model which can properly define the inelastic behavior of panel zones with various column flange thicknesses and to determine a more rational design strength.

• Earthquakes and Structures
• /
• v.18 no.5
• /
• pp.527-542
• /
• 2020

In traditional eccentrically braced steel frames, damages and plastic deformations are limited to the links and the main structure members are required tremendous sizes to ensure elasticity with no damage based on the force-based seismic design method, this limits the practical application of the structure. The high strength steel frames with eccentric braces refer to Q345 (the nominal yield strength is 345 MPa) steel used for links, and Q460 steel utilized for columns and beams in the eccentrically brace steel frames, the application of high strength steels not only brings out better economy and higher strength, but also wider application prospects in seismic fortification zone. Here, the structures with four type eccentric braces are chosen, including K-type, Y-type, D-type and V-type. These four types EBFs have various performances, such as stiffness, bearing capacity, ductility and failure mode. To evaluate the seismic behavior of the high strength steel frames with variable eccentric braces within the similar performance objectives, four types EBFs with 4-storey, 8-storey, 12-storey and 16-storey were designed by performance-based seismic design method. The nonlinear static behavior by pushover analysis and dynamic performance by time history analysis in the SAP2000 software was applied. A total of 11 ground motion records are adopted in the time history analysis. Ground motions representing three seismic hazards: first, elastic behavior in low earthquake hazard level for immediate occupancy, second, inelastic behavior of links in moderate earthquake hazard level for rapid repair, and third, inelastic behavior of the whole structure in very high earthquake hazard level for collapse prevention. The analyses results indicated that all structures have similar failure mode and seismic performance.

• Journal of Korean Society for Geospatial Information Science
• /
• v.24 no.1
• /
• pp.17-24
• /
• 2016

At present, summer cloudburst and local torrential rainfalls have increased in this country, because of climatic change. Therefore, studies on prevention of soil loss have been actively proceeded, and Korea Forest Service has offered landslide hazard map. Landslide hazard map divides risks into 5 classes, by giving weight with 9 kinds of elements. In August 25 2014, soil loss occurred in the whole Oryun Tunnel, Geumjeong-gu, Busan, because of local torrential heavy rain. As a result of comparing with landslide hazard map, the area where soil loss occurred in reality is a safety zone on hazard map. Rainfall, soil map, geological map, forest type map, gradient, drainage network, watershed, basin shape, and efflux of the whole Oryun Tunnel where soil loss occurred were analyzed. As a result of an analysis, it is judged that soil, forest type, much efflux and peak discharge, degree of water network and basin shape of a place where landslide occurred are causes of soil loss. It is judged that efflux, peak discharge, and basin shape by the localized rainfall that is not considered in landslide hazard map of them are the biggest causes of soil loss. It is judged that efflux, peak discharge, degree of water network and basin shape by the rainfall are important through a study on a causual analysis on soil loss in the whole Oryun Tunnel where is one of occurrence area where a lot of propertywere lost by the record local torrential rainfalls. A localized torrential downpour should be prepared by considering these elements on judgement of a landslide hazard area.

• The Korean Journal of Quaternary Research
• /
• v.17 no.2
• /
• pp.17-23
• /
• 2003

In Korea terrestrial fluvial sequences can be used as pedological and sedimentological markers indicating a millenium-scale environmental and climatic changes imprinted in fluvial sub-environments, which in turn are represented by the cyclicity of fluvial sands, backswamp organic muds, and flooding muds intercalations of frostcracked or dessicated brown paleosols. Post LGM and Holocene fluvial and alluvial sedimentary sequences of Korea are formed in such landscapes of coastal, floodplain, backswamp and hillslope areas. Among them, the most outstanding depositional sequences are fluvial gravels, sands and organic mud deposits in coastal, fluvial, or alluvial wetlands. The aim of this study is to explain the sedimentary sequences and palynofloral zones since the last 15,000years, on the basis of organic muds layers intercalated in fluvial sand deposits. Jangheung-ri site of Nam river, Soro-ri site of Miho river, Youngsan rivermouth site in Muan, Oksan-ri site of Hampyeong and Sanggap-ri site of Gochang are illustrated to interpret their sedimentary facies, radiocarbon datings, and palynofloral zonation. Up to the Middle to Late Last Glacial(up to 30-35Ka), old river-bed, flooding, and backswamp sequences contain such arboreal pollens as Pinus, Abies, and Picea, and rich in non-arboreal pollens like Cyperaceae, Gramineae, Ranunculaceae, and Compositae. During the LGM and post-LGM periods until Younger Dryas, vegetation has changes from the sub-alpine conifer forest(up to about 17-11Ka), through the conifer and broad-leaved deciduous forest, or mixed forest (formed during 16,680-13,010yrB.P), to the deciduous and broad-leaved forest (older than 9,500yrB.P). In the Earliest Holocene flooding deposits, fragments of plant roots are abundant and subjected to intensive pedogenic processes. During Holocene, three arboreal pollen zones are identified in the ascending order of strata； Pinus-Colyus zone(mixed conifer and deciduous broad-leaved forest, about up to 10Ka), Alnus-Quercus forest (the cool temperate deciduous broad-leaved forest, about 10Ka-2Ka), and Pinus forest (the conifer forest, about after 2Ka), as examplified in Soro-ri site of Cheonwon county. The palynological zonations of Soro-ri, Oksan-ri, Sanggap-ri, Youngsan estuary, and Gimhae fluvial plain have been recognized as a provisional correlation tool, and zonations based on fluvial backswamp and flooding deposits shows a similar result with those of previous researchers.

• Journal of the Korean GEO-environmental Society
• /
• v.18 no.12
• /
• pp.47-57
• /
• 2017

In this study, a predictive analysis was conducted on sediment disaster hazard area by selecting six research areas (Chuncheon, Seongnam, Sejong, Daejeon, Miryang and Busan) among the urban sediment disaster preliminary focus management area. The models that were used in the analysis were the existing models (SINMAP and TRIGRS) that are commonly used in predicting sediment disasters as well as the program developed through this study (LSMAP). A comparative analysis was carried out on the results as a means to review the applicability of the developed model. The parameters used in the predictions of sediment disaster hazard area were largely classified into topographic, soil, forest physiognomy and rainfall characteristics. A predictive analysis was carried out using each of the models, and it was found that the analysis using SINMAP, compared to LSMAP and TRIGRS, resulted in a prediction of a wider hazard zone. These results are considered to be due to the difference in analysis parameters applied to each model. In addition, a comparison between LSMAP, where the forest physiognomy characteristics were taken into account, and TRIGRS showed that similar tendencies were observed within a range of -0.04~2.72% for the predicted hazard area. This suggests that the forest physiognomy characteristics of mountain areas have diverse impacts on the stability of slopes, and serve as an important parameter in predicting sediment disaster hazard area.

• Journal of the Korean Society of Hazard Mitigation
• /
• v.4 no.3 s.14
• /
• pp.73-81
• /
• 2004

On this study, durability decreasing element caused by salt damage was analyzed elementally and studied with the data of the inside and outside in the country. The design strength and water-cement ratio according to diffusion coefficients of chloride were applied to Fick's diffusion equation. The required over depended on environmental conditions is estimated with endurance period, and the influences on cover according to the transformation of the each parameter were investigated. In consequence, if water-cement ratio decreases and design strength increases, it shows that slowing infiltration velocity of chloride ion can decrease required cover. Especially, it is more effective to use Portland blast-furnace slag cement into high strength concrete in the splash zone environmental conditions in blocking the diffusion of chloride ion. As the result, in the case of the offshore concrete structure needed high durability, it is needed to increase cover($3cm{\sim}8cm$) than minimum standard cover(8cm) according to environmental conditions.

• International Journal of Highway Engineering
• /
• v.17 no.5
• /
• pp.47-56
• /
• 2015

PURPOSES: The purpose of this study is to estimate the impact of variable message signage (VMS) on traffic safety as a function of road curve radius using statistical methods. METHODS: In order to analyze the impact of VMS installations on traffic safety, travel speed, lateral distance, and geometric data relating to road curvature in each study area was acquired and analyzed for the impact of providing VMS information on driver performance and traffic safety using statistical methods including student t-test, Mann-Whitney test, and the Anderson-Darling test for estimating traffic safety hazard zone in each lane. RESULTS: As a result of analyzing driver performance characteristics before and after providing VMS information, it was determined that by providing VMS information, mean travel speed is deceased and vehicles are driven with increased precision, following the centerline in the first and second lanes. Also the results of analyzing traffic safety impacts of VMS indicate that traffic safety performance factors in the first lane of the Gapyeong section can, on average, increase in the left and right side of the lane by 19.22% and 68.98%, respectively, and in the case of the second lane, safety impacts, on average, can increase in both sides by 100%. For the Hongcheon section, traffic safety impacts in the first lane, on average, can increase along the left and right sides of the lane by 32.31% and 47.18%, and within the second lane, traffic safety can be increased along the left and right side of the lane by 10.97% and -0.01%, respectively. CONCLUSIONS: Based on the results of this study, the impact on traffic safety obtained by providing VMS information for road sections with smaller curve radii is greater than can be obtained for road sections with larger curve radii.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2009.03a
• /
• pp.1225-1234
• /
• 2009

As the Wenchuan Earthquake was of high magnitude and shallow seismic focus, it caused great damage and serious geo-hazards. By the field investigation and remote-sensing interpretation after the earthquake and by using means of GIS, the distribution of geo-hazards triggered by the earthquake was analyzed and the conclusions are as follows: (1) the earthquake geo-hazards showed the feature of zonal distribution along the earthquake fault zone and linear distribution along the rivers; (2) the distribution of earthquake geo-hazards had a marked hanging wall effect, for the development density of geo-hazards in the hanging wall of earthquake fault was obviously higher than that in the foot wall and the width of strong development zone in the hanging wall was about 10 km; (3) the topographical slope was a main factor which controlled the development of earthquake geo-hazards and a vast majority of geo-hazards were distributed on the slopes of 20 to 50 degrees; (4) the earthquake geo-hazards had a corresponding relationship with the elevation and micro-landform, for most hazards happened in the river valleys and canyon sections below the elevation of 1500 to 2000 m, particularly in the upper segment of canyon sections (namely, the turning point from the dale to the canyon). Thin ridge, isolated or full-face space mountains were most sensitive to the seismic wave, and had a striking amplifying effect. In these areas, collapses and landslides were most likely to develop; (5) the study also showed that different lithologies determined the types of geo-hazards, and usually, landslides occurred in soft rocks, while collapses occurred in hard rocks.