• Title/Summary/Keyword: building loads

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Aerodynamic loading of a typical low-rise building for an experimental stationary and non-Gaussian impinging jet

  • Jubayer, Chowdhury;Romanic, Djordje;Hangan, Horia
    • Wind and Structures
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    • v.28 no.5
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    • pp.315-329
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    • 2019
  • Non-synoptic winds have distinctive statistical properties compared to synoptic winds and can produce different wind loads on buildings and structures. The current study uses the new capabilities of the WindEEE Dome at Western University to replicate a stationary non-Gaussian wind event recorded at the Port of La Spezia in Italy. These stationary non-Gaussian wind events are also known as intermediate wind events as they differ from non-stationary non-Gaussian events (e.g., downbursts) as well as stationary Gaussian events (e.g., atmospheric boundary layer (ABL) flows). In the present study, the wind loads on a typical low-rise building are investigated for an intermediate wind event reproduced using a continuous radial impinging jet (IJ) at the WindEEE Dome. For the same building model, differences in wind loads between ABL and IJ are also examined. Wind loads on different surface zones on the building, as defined in the ASCE code for design loads, are also calculated and compared with the code.

Analysis of three dimensional equivalent static wind loads of symmetric high-rise buildings based on wind tunnel tests

  • Liang, Shuguo;Zou, Lianghao;Wang, Dahai;Huang, Guoqing
    • Wind and Structures
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    • v.19 no.5
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    • pp.565-583
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    • 2014
  • Using synchronous surface pressures from the wind tunnel test, the three dimensional wind load models of high-rise buildings are established. Furthermore, the internal force responses of symmetric high-rise buildings in along-wind, across-wind and torsional directions are evaluated based on mode acceleration method, which expresses the restoring force as the summation of quasi-static force and inertia force components. Accordingly the calculation methods of equivalent static wind loads, in which the contributions of the higher modes can be considered, of symmetric high-rise buildings in along-wind, across-wind and torsional directions are deduced based on internal forces equivalence. Finally the equivalent static wind loads of an actual symmetric high-rise building are obtained by this method, and compared with the along-wind equivalent static wind loads obtained by China National Standard.

Vibration Analysis of Building Floor Subjected to Walking Loads (보행하중을 받는 건축물 바닥판의 진동해석)

  • 김기철;이동근
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2001.04a
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    • pp.414-421
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    • 2001
  • Recently, the damping effect of building structures are greatly reduced because the use of non-structures members as like curtain wall are decreased and large open space are in need for the service of buildings. Assembly and office buildings with a lower natural frequency have a higher possibility of experiencing excessive vibration induced by human activities as like jumping, running and walking. These excessive vibration make the occupants uncomfortable and the serviceability deterioration. The common method of application of walking loads for the vibration analysis of structures subjected to walking loads is to inflict a series unit walking load and a periodic function at a node. But this method could not consider the moving effect of walking. In this study, natural frequency and damping ratio of plate structure are evaluated by heel drop tests. And new application of equivalent walking loads are introduced for vibration analysis of real slab system subjected to walking loads. The response obtained from the numerical analysis are compared well to the results measured by experimental tests. It is possible to efficiently analyze the vibration of floor which is subjected to walking loads by applying equivalent walking loads.

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Comparative Analysis of Lifting Loads of Tower Cranes by Core Structure Construction Methods

  • Choi, Yong Seok;Kim, Taehoon;Kim, Sangdae
    • International Journal of High-Rise Buildings
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    • v.9 no.3
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    • pp.301-306
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    • 2020
  • In tall building construction, the appropriate control of lifting loads on tower cranes is critical in terms of the construction duration of structural works. The adoption of efficient construction methods can be the most effective way of minimizing the inputs of tower cranes and making a lifting plan and management easier. Based on actual data from a tall building project, this study comparatively analyzes lifting loads of tower cranes by the core structure preceding construction method (CSPCM) and the core structure succeeding construction method (CSSCM). The results revealed that the CSSCM could reduce up to about 56.3% of lifting loads for core works and significantly enhance lifting efficiency compared with the CSPCM. Consequently, this enabled a substantial reduction in the construction duration of structural works. This study provides a practical reference to assist engineers and managers in applying efficient construction methods and lifting equipment operation in tall building projects.

Investigation of 3-D dynamic wind loads on lattice towers

  • Zou, Lianghao;Liang, Shuguo;Li, Q.S.;Zhao, Lin;Ge, Yaojun
    • Wind and Structures
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    • v.11 no.4
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    • pp.323-340
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    • 2008
  • In this paper, the along-wind, across-wind as well as torsional dynamic wind loads on three kinds of lattice tower models are investigated using the base balance technique in a boundary layer wind tunnel. The models were specially designed, and their fundamental frequencies in the directions of the three principal axes are still in the frequency range of the spectra of wind loads on lattice towers. In order to clear contaminations to the spectra of wind loads induced by model resonance, the generalized force spectra of the first mode of the models in along-wind, across-wind and torsional directions were derived based on measured base moments of the models. The RMS generalized force coefficients are also obtained by removing the contributions of model resonance. Finally, the characteristics of the 3-D dynamic wind loads, especially those of the across-wind dynamic loads, on the three kinds of lattice towers are presented and discussed.

Updates to the wind tunnel method for determining design loads in ASCE 49-21

  • Gregory A. Kopp
    • Wind and Structures
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    • v.37 no.2
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    • pp.163-178
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    • 2023
  • The paper reviews and discusses the substantive changes to the ASCE 49-21 Standard, Wind Tunnel Testing for Buildings and Other Structures. The most significant changes are the requirements for wind field simulations that utilize (i) partial turbulence simulations, (ii) partial model simulations for the flow around building Appurtenances, along with requirements for determining wind loads on products that are used at multiple sites in various configurations. These modifications tend to have the effect of easing the precise scaling requirements for flow simulations because it is not generally possible to construct accurate models for small elements placed, for example, on large buildings at the scales typically available in boundary layer wind tunnels. Additional discussion is provided on changes to the Standard with respect to measurement accuracy and data acquisition parameters, such as duration of tests, which are also related to scaling requirements. Finally, research needs with respect to aerodynamic mechanisms are proposed, with the goal of improving the understanding of the role of turbulence on separated-reattaching flows on building surfaces in order to continue to improve the wind tunnel method for determining design wind loads.

Analysis of Office Building HVAC System Drawings (사무용 건축물 공조설비 설계도서 분석)

  • Park, Jong-Il;Kim, Se-Hwan;Kim, Dong-Kyu
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.19 no.11
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    • pp.776-781
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    • 2007
  • Optimized capacity of equipments are essential for energy saving and low cost construction and operation. So we must use proper design data for HVAC system design. We investigated for architectural data, equipment capacity, cooling and heating load design criteria of 52 office buildings. Following research results were obtained by carrying out each task. Office building effective area rate is 63%. The average building cooling load of South Korea is $140W/m^2$ and average heating loads in Seoul and Pusan area are $120{\sim}130W/m^2$ and $70{\sim}80W/m^2$. We also analysised HVAC design criteria. Person ratio in effective building area is $0.2person/m^2$, sensitive and latent heat loads of a person are 60W and 65W, light and equipment loads of office buildings are $25W/m^2$ and $20W/m^2$.

Damage Curves for the Shear Building to the Local Impact (국부충격에 의한 전단건물의 손상곡선)

  • Lee, Sang-Ho;Hwang, Sin-Woo
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.8 no.4
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    • pp.247-256
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    • 2004
  • The damage curves for the 2-story shear building to the impulsive rectangular loads were established with the peak load and Impulse ratio producing the critical displacement. The convolution integrations with the Impulse response matrix and the loads were used to find the responses of the building. The impulse response matrix required in the calculations of the convolution integration were found with the mode superposition method It is shown from the established damage curves that the responses of the top and bottom floor are sensitive to the magnitude and the impulse of the loads respectively.

Interference Effects of Change in Wind Passage of a Building Group on Wind Loads and Wind Environments (건축물군의 바람길변화로 인한 풍하중 상호간섭 및 풍환경)

  • Cho, Kang-Pyo;Hong, Sung-Il;Kim, Mu-Hwan;Lee, Ok-Jin
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2008.04a
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    • pp.402-409
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    • 2008
  • Wind loads and environments in realistic situations surrounded by neighboring buildings may be considerably different from those in idealized or simplified situations such as codes and standards. Interference effects of change in wind passage of a building group on wind loads and wind environments are reviewed. Wind-induced interference effects depend mainly on the building geometry and arrangement of these structures, their orientation and upstream terrain conditions. The most important factor among them may be the arrangement of building structures which can change the wind direction directly. Interference effects regarding wind loads are discussed with examples of window damages by typhoon and of pressure measurements in the boundary layer wind tunnel. Wind environment problems are also discussed, specially underlined on pedestrian comfort and safety. Various evaluation techniques or standards of wind environment are introduced. The change of wind velocity between the panel-type apartment buildings is examined, depending on the distance each other.

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Nonlinear 3-D behavior of shear-wall dominant RC building structures

  • Balkaya, Can;Schnobrich, W.C.
    • Structural Engineering and Mechanics
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    • v.1 no.1
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    • pp.1-16
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    • 1993
  • The behavior of shear-wall dominant, low-rise, multistory reinforced concrete building structures is investigated. Because there are no beams or columns and the slab and wall thicknesses are approximately equal, available codes give little information relative to design for gravity and lateral loads. Items which effect the analysis of shear-wall dominant building structures, i.e., material nonlinearity including rotating crack capability, 3-D behavior, slab-wall interaction, floor flexibilities, stress concentrations around openings, the location and the amount of main discrete reinforcement are investigated. For this purpose 2 and 5 story building structures are modelled. To see the importance of 3-D modelling, the same structures are modelled by both 2-D and 3-D models. Loads are applied first the vertical then lateral loads which are static equivalent earthquake loads. The 3-D models of the structures are loaded in both in the longitudinal and transverse directions. A nonlinear isoparametric plate element with arbitrarily places edge nodes is adapted in order to consider the amount and location of the main reinforcement. Finally the importance of 3-D effects including the T-C coupling between walls are indicated.