• Title/Summary/Keyword: pedestrian wind

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A Study on the Long-Term Behavior of UHPC Pedestrian Cable Stayed Bridge (UHPC 보도사장교의 장기거동에 관한 연구)

  • Chin, Won-Jong;Kim, Young-Jin;Choi, Eun-Suk;Kim, Byung-Suk
    • Proceedings of the Korea Concrete Institute Conference
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    • 2010.05a
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    • pp.109-110
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    • 2010
  • A pedestrian UHPC cable-stayed bridge(Super Bridge I) of the KICT was completed as a test bed. A long-term monitoring system has been installed on the UHPC bridge in order to acquire all types of long-term data such as strain, acceleration, tension force, wind direction and speed, temperature, etc. This system will provide valuable database enabling to assess the long-term behavior of the UHPC pedestrian hybrid cable-stayed bridge. This database will be exploited for the evaluation of the mechanical characteristics and serviceability of the UHPC members so as to estimate the behavioral features of long-span hybrid cable stayed bridges.

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Wind tunnel model studies to predict the action of wind on the projected 558 m Jakarta Tower

  • Isyumov, N.;Case, P.C.;Ho, T.C.E.;Soegiarso, R.
    • Wind and Structures
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    • v.4 no.4
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    • pp.299-314
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    • 2001
  • A study of wind effects was carried out at the Boundary Layer Wind Tunnel Laboratory (BLWTL) for the projected 558-m high free-standing telecommunication and observation tower for Jakarta, Indonesia. The objectives were to assist the designers with various aspects of wind action, including the overall structural loads and responses of the Tower shaft and the antenna superstructure, the local wind pressures on components of the exterior envelope, and winds in pedestrian areas. The designers of the Tower are the East China Architectural Design Institute (ECADI) and PT Menara Jakarta, Indonesia. Unfortunately, the project is halted due to the financial uncertainties in Indonesia. At the time of the stoppage, pile driving had been completed and slip forming of the concrete shaft of the Tower had begun. When completed, the Tower will exceed the height of the CN-Tower in Toronto, Canada by some 5 m.

Prediction and Evaluation of the Wind Environment in Site Planning of Apartment Housing by CFD (아파트 주거의 배치계획에 있어 CFD에 의한 풍환경의 예측과 평가)

  • Sohn, Saehyung
    • KIEAE Journal
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    • v.10 no.2
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    • pp.63-69
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    • 2010
  • Diverse problems in wind environment has occurred through rapid urbanization and growth of high-rise building numbers, This study aims to propose the CFD (Computational Fluid Dynamics) simulation method and evaluation standard of wind environment in site planning of high rise apartment housing. The CFD simulation method proposed in this study is not existing detail simulation, but it is the method that a designer can correct and develop the design through immediate evaluation of design options in concept design phase. Therefore, the proposed CFD simulation method of wind environment in this study uses the BIM based CFD tool in which the 3D model in concept design phase can be used as for the CFD simulation. In this paper, the study examines existing evaluation standards of comfortableness level in wind environment for pedestrian near buildings, and selects new evaluation method which is possible to apply to the proposed CFD simulation method. In addition, it is to examine calculation time-spending and appropriate mesh division method for finding CFD result which is useful to find the best design options in aspect of wind environment in concept design phase. Furthermore, it proposes the wind environment evaluation method through BIM based CFD simulation.

Change of thermal environment in buildings by wind direction (풍향에 따른 건물군에서의 열환경 변화)

  • Kim, Sang-Jin
    • KIEAE Journal
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    • v.12 no.3
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    • pp.27-32
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    • 2012
  • In recent years, the quality of the outdoor thermal environment has come to be regarded as important as that of the indoor thermal environment. Since the outdoor thermal environment is composed of many elements and is affected by many factors, it is not easy to evaluate the impact of each factor separately. Hence, a comprehensive assessment method is required. In order to evaluate the pedestrian level comfort of an outdoor climate, it is necessary to investigate not only wind velocity but also various physical elements, such as temperature, moisture, radiation, etc. Prediction of wind and thermal environment for a large scale buildings is one of the most important targets for research. Wind and thermal change in a city area is a very complicated phenomenon affected by many physical processes. The purpose of this study is to develop a design plan for wind environment at a large Buildings. In this study, we analyze outdoor wind environment and thermal environment on buildings using the CFD (Computational Fluid Dynamics) method. The arrangement of building models is an apartment in Jeonju. These prediction of wind and thermal environment for a large scale buildings is necessary in a plan before a building is built.

Wind direction field under the influence of topography, part I: A descriptive model

  • Weerasuriya, A.U.;Hu, Z.Z.;Li, S.W.;Tse, K.T.
    • Wind and Structures
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    • v.22 no.4
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    • pp.455-476
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    • 2016
  • In both structural and environmental wind engineering, the vertical variation of wind direction is important as it impacts both the torsional response of the high-rise building and the pedestrian level wind environment. In order to systematically investigate the vertical variation of wind directions (i.e., the so-called 'twist effect') induced by hills with idealized geometries, a series of wind-tunnel tests was conducted. The length-to-width aspect ratios of the hill models were 1/3, 1/2, 1, 2 and 3, and the measurements of both wind speeds and directions were taken on a three-dimensional grid system. From the wind-tunnel tests, it has been found that the direction changes and most prominent at the half height of the hill. On the other hand, the characteristic length of the direction change, has been found to increase when moving from the windward zone into the wake. Based on the wind-tunnel measurements, a descriptive model is proposed to calculate both the horizontal and vertical variations of wind directions. Preliminarily validated against the wind-tunnel measurements, the proposed model has been found to be acceptable to describe the direction changes induced by an idealized hill with an aspect ratio close to 1. For the hills with aspect ratios less than 1, while the description of the vertical variation is still valid, the horizontal description proposed by the model has been found unfit.

Will CFD ever Replace Wind Tunnels for Building Wind Simulations?

  • Phillips, Duncan A.;Soligo, Michael J.
    • International Journal of High-Rise Buildings
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    • v.8 no.2
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    • pp.107-116
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    • 2019
  • The use of computational fluid dynamics (CFD) is becoming an increasingly popular means to model wind flows in and around buildings. The first published application of CFD to both indoor and outdoor building airflows was in the 1970's. Since then, CFD usage has expanded to include different aspects of building design. Wind tunnel testing (WTT) on buildings for wind loads goes back as far as 1908. Gustave Eiffel built a pair of wind tunnels in 1908 and 1912. Using these he published wind loads on an aircraft hangar in 1919 as cited in Hoerner (1965 - page 74). The second of these wind tunnels is still in use today for tests including building design ($Damljanovi{\acute{c}}$, 2012). The Empire State Building was tested in 1933 in smooth flow - see Baskaran (1993). The World Trade Center Twin Towers in New York City were wind tunnel tested in the mid-sixties for both wind loads, at Colorado State University (CSU) and the [US] National Physical Laboratory (NPL), as well as pedestrian level winds (PLW) at the University of Western Ontario (UWO) - Baskaran (1993). Since then, the understanding of the planetary boundary layer, recognition of the structures of turbulent wakes, instrumentation, methodologies and analysis have been continuously refined. There is a drive to replace WTT with computational methods, with the rationale that CFD is quicker, less expensive and gives more information and control to the architects. However, there is little information available to building owners and architects on the limitations of CFD for flows around buildings and communities. Hence building owners, developers, engineers and architects are not aware of the risks they incur by using CFD for different studies, traditionally conducted using wind tunnels. This paper will explain what needs to happen for CFD to replace wind tunnels. Ultimately, we anticipate the reader will come to the same conclusion that we have drawn: both WTT and CFD will continue to play important roles in building and infrastructure design. The most pressing challenge for the design and engineering community is to understand the strengths and limitations of each tool so that they can leverage and exploit the benefits that each offers while adhering to our moral and professional obligation to hold paramount the safety, health, and welfare of the public.

An Analysis on Micro-climate Characteristic of Apartments in Beijing, China Using ENVI-met Simulation (ENVI-met를 이용한 중국 베이징 아파트 하절기 미기후 특성 분석)

  • Wu, Jin-Dong;Lee, Jun-Hoo;Yoon, Seong-Hwan
    • Journal of the Architectural Institute of Korea Structure & Construction
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    • v.35 no.8
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    • pp.169-176
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    • 2019
  • The purpose of this study was to analyze outdoor thermal comfort of apartments planning characteristic of pedestrian height in Beijing, China. Selecting 322 apartment complexes with more than 1000 households and more than 10 buildings(including 10 buildings), mainly in Chaoyang District and Tongzhou District to select 32 basic layout types and then 12 typical layout types were select in 32 basic layout types. Finally, the simulation was conducted for the 12 typical layout types using the micro-climate model ENVI-met to evaluate the wind environment, the thermal environment and the comfort. The results of this study as follows: In the parallel arrangement, it has the best outdoor thermal comfort of Slab-East-Parallel(S/E/P). Next is Slab-South-Parallel(S/S/P), Tower-South-Parallel(T/S/P) in turn. In the stagger arrangement, Mixture-South-North and South Stagger-1(M/S/NSS-1) has the best outdoor thermal comfort and Slab-South-North and South Stagger(S/S/NSS), Tower-South-North and South Stagger(T/S/NSS), Mixture-South-North and South Stagger-3(M/S/NSS-3), Mixture-South-North and South Stagger-4(M/S/NSS-4), Mixture-South-North and South Stagger-2(M/S/NSS-2) in turn. In the cluster arrangement, Mixture-Mixture-Cluster-2(M/M/C-2) has the best outdoor thermal comfort and Mixture-Mixture-Cluster-3(M/M/C-3), Mixture-Mixture-Cluster-1(M/M/C-1) in turn. Due to the low wind speed and high air temperature, it is necessary to consider the layout types that can form the wind road at first, such as Mixture-South-North and South Stagger-1(M/S/NSS-1), Slab-South-North and South Stagger(S/S/NSS) and so on.

Consideration for Application of Wind Environment Assement on Ecological Parks in Cities (도시 생태공원의 풍환경 평가 적용에 관한 고찰)

  • Kim, Wonsul;Jung, Il Won;Kwon, Ji-Hye
    • Journal of Wetlands Research
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    • v.21 no.spc
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    • pp.117-122
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    • 2019
  • City parks play an important role in reducing the air pollution and mitigating the city heat island effect caused by global warming. However, from July 2020, restricted parks over 20-year will be partially lifted due to sunset regulation on parks. As a result, the government and local governments have been making efforts to revitalize parks, such as creating ecological parks and securing park sites. However, building winds generated by high-rise buildings constructed around ecological parks in the city may cause discomfort to pedestrians and threaten the ecosystems of plants and animal that live in ecological parks. There are no clearly proposed as standards for wind environment assessment in Korea, but also it has been rarely studied on pedestrian wind environment. In this study, wind environment studies have been reviewed to find the important parameters related to wind environment assessment. Further, wind climate analysis using wind data obtained by Seoul meterological station was performed to examine the possibility of applicability of the wind environment assessment on the city ecological parks.

Comparison of various k-ε models and DSM applied to flow around a high-rise building - report on AIJ cooperative project for CFD prediction of wind environment -

  • Mochida, A.;Tominaga, Y.;Murakami, S.;Yoshie, R.;Ishihara, T.;Ooka, R.
    • Wind and Structures
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    • v.5 no.2_3_4
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    • pp.227-244
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    • 2002
  • Recently, the prediction of wind environment around a building using Computational Fluid Dynamics (CFD) technique comes to be carried out at the practical design stage. However, there have been very few studies which examined the accuracy of CFD prediction of flow around a high-rise building including the velocity distribution at pedestrian level. The working group for CFD prediction of wind environment around building, which consists of researchers from several universities and private companies, was organized in the Architectural Institute of Japan (AIJ) considering such a background. At the first stage of the project, the working group planned to carry out the cross comparison of CFD results of flow around a high rise building by various numerical methods, in order to clarify the major factors which affect prediction accuracy. This paper presents the results of this comparison.

Design for Gwangjang-dong Neighbourhood Park in Gwangjin-gu, Seoul (서울 광진구 광장동 기능 복합적 근린공원 설계)

  • Lee, Gwan-Gyu;Han, Seon-A
    • Journal of the Korean Institute of Landscape Architecture
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    • v.34 no.4 s.117
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    • pp.61-68
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    • 2006
  • A park will soon be developed in an area of Gwangjang-dong, Gwangjin-gu. The place has been a patch of green space for years, isolated by driveways and apartment complexes and abandoned. This article describes plans to infuse the abandoned green space with history, ecology, culture, and sports. The facilities that are to be constructed in and around the green space are positioned to take into account the path of the sun and the location of the curvilinear green space axis. The cultural space is planned as a centerpiece of the park, linked with the sports facilities. The overall framework is arranged in harmony with nearby elementary schools, parks, public facilities, athletic facilities, parking lots, and apartment complexes. The themed circulation route was constructed according to the environmental conditions and the spatial plan. In addition, the historical space is planned to work in close conjunction with the cultural space, and the streets and pedestrian pathways have characters of their own. The established contour lines will be carefully preserved, and an ecological pond will. The facilities, such as the outdoor performance stage, the outdoor art gallery, the Monument of Wind represented by a sail, and the pedestrian bridge in memory of Acha-sansung, are positioned for spatial balance and to provide a nexus. The bamboo forest, designed to foster the experience of sound effects, the architectural thematic plants, and the ecological pond are positioned to connect to each other around the greenspace axis. The main facilities are the outdoor theater, the bamboo forest, the Acha-sansung bridge, the Monument of Wind, the ecological pond, the four-season flower garden, parking lots, playgrounds, circulatory athletic pathways, and the tennis court.