• Title/Summary/Keyword: Construction disaster

Search Result 1,511, Processing Time 0.083 seconds

Meteorological Information for Red Tide : Technical Development of Red Tide Prediction in the Korean Coastal Areas by eteorological Factors (적조기상정보 : 기상인자를 활용한 연안 적조예측기술 개발)

  • Yoon Hong-Joo
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.9 no.4
    • /
    • pp.844-853
    • /
    • 2005
  • Red tide(harmful algae) in the Korean Coastal Waters has a given a given damage to the fishery every year. However, the aim of our study understands the influence of meteorological factors (air and water temperature, precipitation sunshine, solar radiation, winds) relating to the mechanism of red tide occurrence and monitors red tide by satellite remote sensing, and analyzes the potential area for red tide occurrence by GIS. The meteorological factors have directly influenced on red tide formation. Thus, We want to predict and apply to red tide formation from statistical analyses on the relationships between red tide formation and meteorological factors. In future, it should be realized the near real time monitoring for red tide by the development of remote sensing technique and the construction of integrated model by the red tide information management system (the data base of red tide - meteorological informations. Finally our purpose is support to the prediction information for the possible red tide occurrence by coastal meteorological information and contribute to reduce the red tide disaster by the prediction technique for red tide.

Suitable Site Prediction of Erosion Control Dam by Sediment (산지사면에 있어서 퇴사량에 의한 사방댐의 시공적지 예측)

  • Ma, Ho-Seop;Jeong, Won-Ok
    • Journal of Korean Society of Forest Science
    • /
    • v.96 no.3
    • /
    • pp.300-306
    • /
    • 2007
  • This study was carried out to analyze the characteristics of forest environmental and stream morphological factors by using the quantification theory (I) for prediction of the suitable dam site. The results obtained from this study were summarized as follows; The selection of suitable site for erosion control dam was estimated by normalized score of each category. And the prediction method of suitable site for erosion control dam divided into class I (Very suitable site), II (Suitable site), and III (Poor suitable site) for the convenience of use. In conclusion, if we select the suitable site for construction of erosion control dam for disaster prevention, we could save the loss of tremendous budget, avoid the poor suitable site due to subjective judgment, and it would promote the functions of erosion control dam.

Evaluation of Wet-Mixed High Strength Sprayed Polymer Mortar for Fire Resistance (내화용 고강도 습식 스프레이 폴리머 모르타르의 화재 저항성 평가)

  • Won, Jong-Pil;Choi, Seok-Won;Park, Chan-Gi;Park, Hae-Kyun
    • Journal of the Korea Concrete Institute
    • /
    • v.18 no.4 s.94
    • /
    • pp.559-568
    • /
    • 2006
  • The purpose of this study is to evaluate the mechanical performance and fire resistance of wet-mixed high strength sprayed polymer-modified mortar in order to protect tunnel lining system which are in the event of fire disaster. Since the current commercial fire-resistant materials reproduce the low strength issue of mortar, this study aims to provide an enhanced fire-resistant mortar with a proper strength. Normally, a large temperature gradient phenomenon arise in the vicinity of free surfaces which are fully exposed in the event of persistent flame. Thereby, the determination of optimal cover depth of wet-mixed high strength sprayed polymer-mortar(WHSPM) is important for fire-resistance of tunnel lining system. With comparison of current commercial fire-resistance materials and WHSPM, the experimental result of WHSPM shows the better fire-resistant performance than the others. In addition, the cover limitation should be controlled by minimum 4cm depth in order to avoid fire-induced damage.

Study on Subsurface Collapse of Road Surface and Cavity Search in Urban Area (도심지 노면하부 지반함몰 및 공동탐사 사례 연구)

  • Chae, Hwi-Young
    • Tunnel and Underground Space
    • /
    • v.27 no.6
    • /
    • pp.387-392
    • /
    • 2017
  • Recently, road cave-ins, also referred to as ground sinking, have become a problem in urban environments. Public utility facilities such as sewage pipelines, communications pipes, gas pipes, power cables, and other types of underground structures are installed below the roads. It was reported that cave-ins are caused by the aging and lack of proper maintenance of underground facilities, as well as by construction problems. A road cave-in is first initiated by the formation of cavities typically induced by the breakage of underground pipelines. The cavities then grow and reach the base of the pavement. The traffic load applied at the surface of the roads causes an abrupt plastic deformation. This type of accident can be considered as a type of disaster. A road cave-in can threaten both human safety and the economy. It may even result in the loss of human life. In the city of Seoul, efforts to prevent damage before cave-ins occur have been prioritized, through a method of discovering and repairing joints through the 3D GPR survey.

A Comparative Assessment of the Efficacy of Frequency Ratio, Statistical Index, Weight of Evidence, Certainty Factor, and Index of Entropy in Landslide Susceptibility Mapping

  • Park, Soyoung;Kim, Jinsoo
    • Korean Journal of Remote Sensing
    • /
    • v.36 no.1
    • /
    • pp.67-81
    • /
    • 2020
  • The rapid climatic changes being caused by global warming are resulting in abnormal weather conditions worldwide, which in some regions have increased the frequency of landslides. This study was aimed to analyze and compare the landslide susceptibility using the Frequency Ratio (FR), Statistical Index, Weight of Evidence, Certainty Factor, and Index of Entropy (IoE) at Woomyeon Mountain in South Korea. Through the construction of a landslide inventory map, 164 landslide locations in total were found, of which 50 (30%) were reserved to validate the model after 114 (70%) had been chosen at random for model training. The sixteen landslide conditioning factors related to topography, hydrology, pedology, and forestry factors were considered. The results were evaluated and compared using relative operating characteristic curve and the statistical indexes. From the analysis, it was shown that the FR and IoE models were better than the other models. The FR model, with a prediction rate of 0.805, performed slightly better than the IoE model with a prediction rate of 0.798. These models had the same sensitivity values of 0.940. The IoE model gave a specific value of 0.329 and an accuracy value of 0.710, which outperforms the FR model which gave 0.276 and 0.680, respectively, to predict the spatial landslide in the study area. The generated landslide susceptibility maps can be useful for disaster and land use planning.

Experimental Study on the Adjustment Processes of a Series of Mining Pits in the Dredged Channels (준설하천에서 직렬로 배열된 웅덩이의 적응에 관한 실험적 연구)

  • Jang, Chang-Lae;Lee, Gi-Ha
    • Korean Journal of Ecology and Environment
    • /
    • v.44 no.4
    • /
    • pp.385-395
    • /
    • 2011
  • The adjustment processes and responses of a series of mining pits by sand or gravel mining were investigated by laboratory experiments. The filling processes of the two pits were affected by the bars developed in the upstream of the channel. However, the bars were not developed and the bed was degradated in the downstream of the pits due to little sediment flow, which was trapped in the pits. The submerged angle of repose in the pits was nearly constant when the pits were being filled. After the filling processes of the pits were finished, the pit was speedily filled with sediment, and the bed was aggradated and migrated with speed. However, the angle of repose decreased. As the distance between the upstream pit and the downstream pit increased, the bed of the pit downstream was tailcutted and degradated. The migration speed of the pit decreased. However, the dimensionless pit depth increased as the distance between the pits increased. The dimensionless pit depth increased with time.

A Basic Study on Required Performance and Development Direction of Fire Resistance Wall on High-rise Building (초고층 건축물용 내화벽체 요구성능 및 개발방향 설정을 위한 기초연구)

  • Kim, Dae-Hoi;Park, Soo-Young
    • Fire Science and Engineering
    • /
    • v.25 no.4
    • /
    • pp.1-7
    • /
    • 2011
  • Recently the interest in disaster prevention on super tall buildings is increasing. Especially in fire, against increasing of evacuation time due to high-rise, It is being tried to minimize the fire spread in building. Fire compartments using the fire-resistant wall and door, typical method to control the fire spread in buildings, delay the fire spread to other compartments and consequently evacuation time increases. But the existing provisions adjure only 2-hour fire resistance with maximum limit regardless of the super tall buildings, so this is a obstacle for research and development of the fire resistance wall in super tall buildings. In this study, we reviewed the fire resistance ratings of the wall, and presented the development directions for the fire resistance wall in super tall buildings considering fire resistance, construction and application of the wall.

A Study on the Risk of Particulate Materials Included in the Combustion Products of Building Materials (건축재료 연소생성물에 포함된 입자상 물질의 위험성에 관한 연구)

  • Kim, Nam-Kyun;Cho, Nam-Wook;Rie, Dong-Ho
    • Fire Science and Engineering
    • /
    • v.30 no.1
    • /
    • pp.43-48
    • /
    • 2016
  • In this study, the experiment to confirm the risks of particulate material was carried out as a precedent study for developing the toxicity evaluation method of combustion products including the toxicity of particulate material. In the experiment, the test result of filtering and exposing particulate material among combustion products and that of exposing combustion products including particulate material were compared and analyzed by analyzing changes in average movement stop time according to the installation of Membrane filter between the stirring box and test box through the gas toxicity test of the same specimen to filter particulate material among combustion products. As the test result, in case of installing a filter, the average movement stop time of an experimental rat increased by up to 264% in case of lumber specimen and up to 179% in case of urethane specimen. Through such result, the necessity of identifying the toxicity of particulate material and carrying out quantitative toxicity test for particulate material was confirmed.

X3D Based Web Visualization by Data Fusion of 3D Spatial Information and Video Sequence (3D 공간정보와 비디오 융합에 의한 X3D기반 웹 가시화)

  • Sohn, Hong-Gyoo;Kim, Seong-Sam;Yoo, Byoung-Hyun;Kim, Sang-Min
    • Journal of Korean Society for Geospatial Information Science
    • /
    • v.17 no.4
    • /
    • pp.95-103
    • /
    • 2009
  • Global interests for construction of 3 dimensional spatial information has risen due to development of measurement sensors and data processing technologies. In spite of criticism for the violation of personal privacy, CCTV cameras equipped in outdoor public space of urban area are used as a fundamental sensor for traffic management, crime prevention or hazard monitoring. For safety guarantee in urban environment and disaster prevention, a surveillance system integrating pre-constructed 3 dimensional spatial information with CCTV data or video sequence is needed for monitoring and observing emergent situation interactively in real time. In this study, we proposed applicability of the prototype system for web visualization based on X3D, an international standard of real time web visualization, by integrating 3 dimensional spatial information with video sequence.

  • PDF

Inundation Simulation on a Vertical Dock Using Finite Element Storm Surge Model (유한요소 폭풍해일 모형을 이용한 직립안벽에 대한 범람모의)

  • Suh, Seung-Won;Lee, Hwa-Young
    • Journal of Korean Society of Coastal and Ocean Engineers
    • /
    • v.24 no.4
    • /
    • pp.235-246
    • /
    • 2012
  • Typhoon induced surge simulations are done to make an establishment of coastal disaster prevention plan. To apply efficient run-up and overtopping on vertical harbor docks, in which prevailing wet-dry scheme cannot be satisfied due to infinite steepness, an imaginary internal barrier concept introduced and analyzed. Before real application on the Mokpo harbor area, feasibility tests are done on an idealized simple geometry and as a result it is found that the moderate width of the barrier might be 1 m. The threshold value of the minimum wet depth $H_{min}$ for land area, which behaves sensitive role in inundation area and depth, depends on grid size. However it is revealed that 0.01 m is adequate value in this fine finite element with 10 m spacing. A hypothetical typhoon of 100 years return period in central pressure and maximum velocity is generated based on historical tracks. Simulation of possible inundation on Mokpo area is performed with asymmetrical vortex of hypothetical typhoon and wave coupling. Model results show general agreement in pattern compared to other's prediction, however possibility of inundation enlargement is expected in harbor area.