• Title/Summary/Keyword: Velocity Pressure Exposure Coefficient

Search Result 6, Processing Time 0.021 seconds

Estimation of Velocity Pressure Exposure Coefficient using GIS (GIS를 이용한 풍속고도분포계수 산정)

  • Seong, Min-Ho;Choi, Se-Hyu
    • Spatial Information Research
    • /
    • v.19 no.1
    • /
    • pp.13-19
    • /
    • 2011
  • As an urbanization is in progress, the change of the planimetric features and topography including high-rise residential buildings commonly occur. The change of the planimetric features and topography causes occurrence of the strong wind and wind speed increase or decrease due to the effect of planimetric features and topography on the windward side even though the wind blows with the same speed. In the design standard, this change by wind speed is defined as the velocity pressure exposure coefficient, the value of coefficient is estimated and reflected by ground surface roughness, but in a reality, ground surface roughness is determined in accordance with the subjective judgement of designer and then the velocity pressure exposure coefficient is estimated, moreover the research and data for classification of ground surface roughness are insufficient. In this paper, we will estimate the velocity pressure exposure coefficient by the quantified method for classifying ground surface roughness by using GIS according to the height of a building targeting area where high-rise residential buildings are built lately. When the structure subjected to wind load is designed, reasonability of design and safety of structure will be more improved by using the estimation method of velocity pressure exposure coefficient presented in this study.

Development of Estimation Method for Velocity Pressure Exposure Coefficient of Buildings Based on Spatial Information (공간정보기반 건축물의 풍속고도분포계수 산정 방법 개발)

  • SEO, Eun-Su;CHOI, Se-Hyu
    • Journal of the Korean Association of Geographic Information Studies
    • /
    • v.20 no.2
    • /
    • pp.32-46
    • /
    • 2017
  • Recent rapid urban expansion and crowding of various industrial facilities has affected the features of a significant part of downtown area, resulting in areas having buildings with a wide range of height and the foothills. To compute a velocity pressure exposure coefficient, namely the design wind speed factor, this study defines ground surface roughness by utilizing concentration analysis for the height of each building. After obtaining spatial data by extracting a building layer from digital maps, the study area was partitioned for the concentration analysis and to allow investigation of the frequency distribution of building heights. Concentration analysis by building height was determined with the Variation-to-Means Ratio (VMR) and Poisson distribution analysis using a buildings distribution chart, with statistical significance determined using Chi-square verification. Applying geographic information systems (GIS) with the architectural information made it possible to estimate a velocity pressure exposure coefficient factor more quantitatively and objectively, by including geographic features, as compared to current methods. Thus, this method is expected to eliminate inaccuracies that arise when building designers calculate the velocity pressure exposure coefficient in subjective way, and to help increase the wind resistance of buildings in a more logical and cost-effective way.

Estimation of Design Wind Speed for Building Using Spatial Information Analysis (공간정보 분석을 통한 건축물의 설계풍속 산정)

  • Lee, Seong-Yun;Jo, Hyun-Jae;Lee, Hyun-Ki;Choi, Se-Hyu
    • Spatial Information Research
    • /
    • v.23 no.3
    • /
    • pp.79-89
    • /
    • 2015
  • Once the building is higher than certain size, the wind effect plays very important role in structure design. Moreover, this is more important in Korea because dangerous phenomena like typhoons are common. Rational wind resistant design is being magnified considering the global flow and climate changes. This research presented the estimation method of design wind load using spatial information analysis based on 1:5,000 digital map and performed comparative analysis with actual application cases. The wind velocity pressure exposure coefficient and topographic coefficient turned out to be more quantitative and rational when calculated through the proposed method. The time and cost are comparatively low when compared with traditional method which contribute to the economic and rational wind resistant design.

An Analytic Study on the Effect of Carbon Disulfide on the Blood Pressure (이황화탄소 폭로가 혈압에 미치는 영향에 관한 분석적 연구)

  • Park, Jong-Tae;Kim, Hae-Joon;Yum, Yong-Tae;Paek, Do-Myung
    • Journal of Preventive Medicine and Public Health
    • /
    • v.27 no.3 s.47
    • /
    • pp.581-595
    • /
    • 1994
  • To investigate the effect of carbon disulfide on blood pressure, the BP measurements in the periodic health examination results and the medical records of factory clinic were reviewed. The study subjects were composed of 1336 male and 544 female workers, who were categorized into three groups by the exposure status-highly exposed, moderately exposed and non-exposed group. The results of the study were as follows; 1. The age-adjusted mean systolic and diastolic BP of male workers were 122.35 mmHg/79.11 mmHg in highly exposed, 121.57mmHg/79.05mmHg in moderately exposed and 122.67mmHg/82.27mmHg in non-exposed group. For female workers, BPs were 115.13mmHg/74.49mmHg in moderately exposed and 113.48mmHg/74.30mmHg in non-exposed group. 2. In multiple regression analysis of maximum BP against Age and tenure, the slope coefficients of age and tenure on the systolic BP were 0.379, 0.667 respectively and those on the diastolic BP were 0.331, 0.405 respectively in highly exposed male workers. Tenure was a significant variable in this study. For female workers, however the slope coefficients of tenure on BP were significant only for systolic BP of moderately-exposed group. 3. In multiple regression analysis of Bp against age, cumulative exposure index (CEI), cholesterol, all the variables showed significant slope coefficients in male, but age and CEI on systolic BP were significant for female workers (p<0.05). 4. In the multiple analysis of the amount of Bp change and the velocity of Bp change among male workers, the slope coefficients of tenure tended to increase as exposure level increased. Among female workers, the slope coefficients of tenure were significant on the amount of Bp change and the velocity of Bp change in moderately exposed group.

  • PDF

Estimating Method of Surface Roughness Using Geographic Information (지리정보를 이용한 지표면조도 산정 방법)

  • CHOI, Se-Hyu;SEO, Eun-Su
    • Journal of the Korean Association of Geographic Information Studies
    • /
    • v.18 no.3
    • /
    • pp.1-10
    • /
    • 2015
  • Rapid urban expansion and densification of the various industrial facilities affect the changes of topography and building in urban areas. Even if buildings proceed with high rise, they get mixed with low-rise buildings such as houses and industrial parks that have existed in the area. This may confuse the designer in estimating a surface roughness, an important factor in calculating the design wind velocity of building. This study analyzed the surface roughness by using a geographic information. Referring to the criteria of each country's building code, this study proposed a method to distinguish the surface roughness depending on the height of the surrounding buildings where the design building is located and calculated the surface roughness using 1:5000 topographic map and GIS. It is expected to solve problems that an existing designer calculates the surface roughness in a subjective manner and to help to design more rational buildings resistant to wind.

Estimation Method of the Design Wind Load of Soundproof Wall Using GIS (GIS를 이용한 방음벽의 설계풍하중 산정방법)

  • Lee, Dong-Ho;Choi, Se-Hyu
    • Spatial Information Research
    • /
    • v.23 no.5
    • /
    • pp.75-85
    • /
    • 2015
  • Recently deformed or destroyed of soundproof wall by local winds and typhoon has increased. This research proposed the estimation method of the design wind load of soundproof wall using spatial information analysis based on 1:5,000 digital map and performed comparative analysis with actual application cases. According to the result of quantitative evaluation using GIS, the surface roughness in the downtown area packed with buildings was III and the surface roughness in the suburban district with a relatively small number of buildings was II and the surface roughness in the district packed with open areas and typical farmhouses was I. This shows that the wind load of the soundproof walls reflecting the actual surface conditions was estimated. If the quantitative GIS analysis presented in this study is applied to wind-resistant design of soundproof walls, it is supposed that this will be helpful in more rational wind-resistant design by remedying the existing problem in which the wind load varies depending on designer's subjectivity.