• Title/Summary/Keyword: wind-induced pressure

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Pile and adjacent ground behaviors depending on horizontal offset between pile and tunnel subjected to horizontally loaded single pile (수평하중을 받는 단일 말뚝 하부 터널굴착 시 말뚝-터널 수평이격거리에 따른 말뚝 및 인접 지반 거동)

  • Ahn, Ho-Yeon;Oh, Dong-Wook;Lee, Yong-Joo
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.19 no.5
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    • pp.685-703
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    • 2017
  • Recently, as the number of high-rise building and earthquake occurrence are increasing, it is more important to consider horizontal load such as wind and seismic loads, earth pressure, for the pile foundation. Also, development of underground space in urban areas is more demanded to meet various problem induced by growing population. Many studies on pile subjected to horizontal load have been conducted by many researchers. However, research regarding interactive behavior on pile subjected to horizontal load with tunnel are rare, so far. In this study, therefore, study on the behaviors of ground and horizontal and vertical loads applied to single pile was carried out using laboratory model test and numerical analysis. The pile axial force and ground deformation were investigated according to offset between pile and tunnel (0.0D, 1.0D, 2.0D: D = tunnel diameter). At the same time, close range photogrammetry was used to measure displacement of underground due to tunnelling during laboratory model test. The results from numerical analysis were compared to that from laboratory model test.

A Study of the Characteristics of Heavy Rainfall in Seoul with the Classification of Atmospheric Vertical Structures (대기연직구조 분류에 따른 서울지역 강한 강수 특성 연구)

  • Nam, Hyoung-Gu;Guo, Jianping;Kim, Hyun-Uk;Jeong, Jonghyeok;Kim, Baek-Jo;Shim, Jae-Kwan;Kim, Byung-Gon
    • Journal of the Korean earth science society
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    • v.40 no.6
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    • pp.572-583
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    • 2019
  • In this study, the atmospheric vertical structure (AVS) associated with summertime (June, July, and August) heavy rainfall in Seoul was classified into three patterns (Loaded Gun: L, Inverted V: IV, and Thin Tube: TT) using rawinsonde soundings launched at Osan from 2009 to 2018. The characteristics of classified AVS and precipitation property were analyzed. Occurrence frequencies in each type were 34.7% (TT-type), 20.4% (IV-type), 20.4% (LG-type), and 24.5% (Other-type), respectively. The mean value of Convective Available Potential Energy (1131.1 J kg-1) for LG-types and Storm Relative Helicity (357.6 ㎡s-2) for TT-types was about 2 times higher than that of other types, which seems to be the difference in the mechanism of convection at the low level atmosphere. The composited synoptic fields in all cases showed a pattern that warm and humid southwesterly wind flows into the Korean Peninsula. In the cases of TT-type, the low pressure center (at 850 hPa) was followed by the trough in upper-level (at 500 hPa) as the typical pattern of a low pressure deepening. The TT-type was strongly influenced by the low level jet (at 850 hPa), showing a pattern of connecting the upper- and low-level jets. The result of analysis indicated that precipitation was intensified in the first half of all types. IV-type precipitation induced by thermal instability tended to last for a short term period with strong precipitation intensity, while TT-type by mechanical instability showed weak precipitation over a long term period.