• Title/Summary/Keyword: Buoyancy prevention method

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Characteristics of Positive Pressure Distribution in Vertical Drainage Method to Prevent Buoyance (부력방지를 위한 연직배수공법의 양압력 분포 특성 분석)

  • Jongin Hong;Namcheol Kim;Youngshin Park;Donghyuk Lee
    • Journal of the Korean GEO-environmental Society
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    • v.24 no.10
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    • pp.33-39
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    • 2023
  • As interest in the use of underground spaces increases, safety against water pressure acting on underground structures is required. In Korea, various buoyancy prevention methods are used to control such underground water pressure, and among them, the vertical drainage method with excellent economic efficiency, constructionability and stability has recently been introduced and applied. However, in the case of the vertical drainage method designed and constructed in the field, it is often designed and constructed depending on numerical analysis, making it difficult to expect practical stability judgment. Accordingly, in this study, an experiment was conducted to measure both pressure by installing a vertical drainage system using a model soil. Based on the measured value by the experiment and the numerical analysis value, we intend to compare and analyze the action positive pressure and use it as basic data for field application.

A fundamental study on the jet fan capacity for smoke control considering thermal buoyancy force in tunnel fires (터널 화재 시 열부력을 고려한 제연용 제트팬 용량산정에 관한 기초 연구)

  • Lee, Ho-Hyung;Choi, Pan-Gyu;Jo, Jong-Bok;Lee, Seung-Chul;Lee, Chang-Woo
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.20 no.2
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    • pp.501-511
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    • 2018
  • As a result of the recent revision of the 'Guideline for Installation and Management of Fire Prevention Facility in Road Tunnels', the thermal buoyancy has to be taken into account when calculating the capacity of jet fans for smoke control in tunnel fires. However, there is no detailed methodologies for considering thermal buoyancy, so further study is needed. In this study, the thermal buoyancy in the tunnel is calculated by 3-D numerical simulation to consider the thermal buoyancy in case of fire in tunnels, and the relationship between heat buoyancy and vehicle drag, And the method of calculating the capacity of the jet fan for smoke control in tunnels. According to the analysis results, heat buoyancy acts as a resistance force in the case of a down-slope tunnel, and the pressure rise of jet fan for smoke control is not simply determined by the value of heat buoyancy at the entrance of the tunnel and the value of the vehicle drag at the exit. And it is analyzed that it is necessary to carry out a comprehensive review according to the location of the fire vehicle in tunnels.

A Study on the Controller of Integration Smoke Control System (통합 제연시스템의 컨트롤러 개발에 관한 연구)

  • Lee, Dong-Myung
    • Fire Science and Engineering
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    • v.20 no.1 s.61
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    • pp.77-82
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    • 2006
  • This study defined engineering mechanism and compensation method to establish reference pressure of smoke control zone with atmospheric pressure that is compensated for temperature. The reliable controller of integration smoke control was developed by establishing the specifications, algorithms and constructing engineering data. The development of controller for integration smoke control can cut down number of processes, manufacturing and installation cost by removing pressure measurement pipe established separately for non smoke control zone, and improve the accuracy of pressure differential by embedding pressure measurement ports for non smoke control zone. More correct and reliable pressure differentials can be obtained by the central control from controller of integration smoke control rather than the existent individual control. This will provide the basics and the flexibility to the integral smoke control system and accordingly improve the performance of disaster prevention.

A Study on the Automatic Pressure Differential Sensor Development of Smoke Control Zone (제연구역의 자동 차압센서 개발에 관한 연구)

  • Lee, Dong-Myung
    • Journal of the Korean Society of Hazard Mitigation
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    • v.5 no.3 s.18
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    • pp.23-28
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    • 2005
  • This study defined engineering mechanism and compensation method to establish reference pressure of smoke control zone with atmospheric pressure that is compensated for temperature. The reliable pressure differential sensor was developed by establishing the specifications, algorithms and constructing engineering data. The development of pressure differential sensor can cut down number of processes, manufacturing and installation cost by removing pressure measurement pipe established separately for non smoke control zone, and improve the accuracy of pressure differential by embedding pressure measurement ports for non smoke control zone. More correct and reliable pressure differentials can be obtained by the central control rather than the existent individual control. This will provide the basics and the flexibility to the integral smoke control system and accordingly improve the performance of disaster prevention.

Evaluation on the Vibration Performance for Void-deck Slab Combined with Deck Plate and Polystyrene Void Foam (데크플레이트와 경량성형재가 결합된 중공슬래브의 진동성능에 대한 실물실험 평가)

  • Cho, Seung-Ho;Roh, Young-Sook
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.21 no.3
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    • pp.86-92
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    • 2017
  • The possibility to development of floor vibration problem is larger in case of long span structure under service loads. Therefore, to improve the vibration performance of the floor, increasing of its thickness is a common method. But, increasing of thickness can lead to increase of slab self weight and reduce the effectiveness of the building. For this reason, attention for voided slab which reduces the self-weight is increasing. Hence, voided deck slab combined with deck plate and polystyrene void foam which has buoyancy prevention capacity and much developed construct ability has bee developed. By using the developed voided slab, vibration performance of a mock-up building structure has been investigated in the current study. The results according to analysis showed that they can be implemented in living and bedroom which are considered as 1st grade on the basis of "Residential Evaluation Guidelines for Vibration of Buildings" by the Architectural Institute of Japan.