Design recommendations for wind loading on buildings of intermediate height

1989 ◽  
Vol 16 (6) ◽  
pp. 910-916 ◽  
Author(s):  
T. Stathopoulos ◽  
M. Dumitrescu-Brulotte

The National Building Code of Canada (NBCC) specifies wind loads for the design of tall (height, H > width, W) and low (H < 10 m, or H < W and H < 20 m) buildings. Since there are no specifications for the design of buildings of intermediate height, the present project has been undertaken to help define wind loads appropriate for the design of such buildings. The experimental study was carried out at the boundary layer wind tunnel of the Centre for Building Studies at Concordia University. The methodology used for this project consisted of testing five square building models (12, 25, 55, 100, and 145 m high) under conditions simulating strong turbulent wind blowing over an open country terrain exposure. Both the lowest and the tallest buildings were tested for validation purposes. Statistics of wind induced pressures were measured at several points and areas on the walls and the roof of all buildings for both normal and oblique wind directions. Experimental data show good agreement with previous studies of buildings of similar height tested under different environmental and proximity conditions. Results for the intermediate height buildings are presented in the paper. Wind pressures are compared with the NBCC specifications for low and tall buildings. Key words: building, code, design, loads, pressure, roof, wall, wind.

1988 ◽  
Vol 15 (4) ◽  
pp. 570-578 ◽  
Author(s):  
T. Stathopoulos ◽  
A. Baskaran

This paper reviews the available experimental data regarding the effect of parapet configurations on the wind loading of roofs of buildings of various geometries and under different exposures. Particular reference is given to the recent study carried out by the authors in a boundary layer wind tunnel. This study deals with the effects of wind on a variety of flat roofs with and without parapets when exposed to simulated open country and urban terrains. Geometrical parameters examined include the effect of building height (ranging from 12 to 145 m) and parapet height (0–3 m) on both local and area-averaged roof pressures for a variety of wind directions. Results show that parapets generally reduce the high suctions on roof edges and may slightly increase the suctions on the interior areas of the roof. Roof corner suctions, however, increase significantly for low parapet heights.Additional parapet configurations have been examined to reduce these high local corner suctions. Parapet cuts or slots around corners have proven to be effective in this respect. The effect of one-sided, as opposed to perimetrical, parapet has also been examined. Extensive comparisons of the data and recommendations for the wind load provisions of the National Building Code of Canada (NBCC) and the American National Standards Institute (ANSI) are also made. Key words: building, code, design, loads, pressure, project, roof, wind.


1990 ◽  
Vol 17 (4) ◽  
pp. 569-577 ◽  
Author(s):  
T. Stathopoulos ◽  
H. D. Luchian

The paper describes an experimental study for the evaluation of wind pressures on buildings with roofs of two different heights, such as one building with roofs at two levels or, more commonly, two flat-roofed buildings in a row. The study is experimental and consists of an extensive series of tests in a boundary layer wind tunnel simulating the flow over an open country terrain exposure. The basic model of the study has been designed and constructed in sections so that it can represent flat roofs in steps of different relative heights and widths. The maximum height of the model is variable and can represent a building up to 60 m high. The results of the study for buildings with a two-level flat roof are discussed in the paper. Data are presented in pressure coefficient form (both mean and peak values) measured locally on a number of pressure taps placed at strategic locations on the roof and wall sections of the model. The results of the study are compared with the flat-roof specifications described in the American National Standards Institute wind standard and the National Building Code of Canada. It has been found that some modifications of these standards are required to accommodate the wind loading of these building configurations. In particular, the inclusion of positive pressure coefficients must be considered for stepped roofs. Key words: building, code, design, loads, pressure, roof, wall, wind.


2000 ◽  
Vol 27 (5) ◽  
pp. 1059-1072 ◽  
Author(s):  
Ted Stathopoulos ◽  
Kai Wang ◽  
Hanqing Wu

Wind pressure coefficients for gable roofs of low buildings are strongly dependent on roof angle, particularly for intermediate roof slopes (roof angle 10°-30°). This paper addresses the suitability of wind pressure coefficients specified in the National Building Code of Canada (NBCC) for gable roofs in the intermediate slope range. In a recent research study, a series of low building models with different roof slopes were tested in a boundary layer wind tunnel under simulated open country conditions. This was different from the original study in the 1970s, which produced the current wind provisions on the basis of a model tested only for a single roof slope (4:12) in this intermediate roof slope range. The results of the study suggest that a modification of the wind provisions of NBCC would be warranted to make them more representative of the true local and area-averaged wind loads imposed on gable roofs of intermediate slope.Key words: building, code, design, pressure, roof, standard, wind.


2013 ◽  
Vol 351-352 ◽  
pp. 347-350
Author(s):  
Lun Hai Zhi

This paper present some selected results of wind tunnel tests carried out on a typical super-tall building The variations of wind loads in the three orthogonal directions with wind attack direction were evaluated. The cross-correlations among various wind loading components were presented and discussed in detail. Furthermore, the across-wind spectral characteristics were studied and an empirical formula for estimation of the across-wind overturning moment spectrum for the super-tall building is presented. The output of this study is expected to be of considerable interest and practical use to professionals and researchers involved in the design of super-tall buildings.


2018 ◽  
Vol 232 ◽  
pp. 02028
Author(s):  
Bowei Liu ◽  
Yi Sun ◽  
Mei Wang

The wind loads could be increased by the complex hilly terrain. In order to consider this threat, computational simulations about wind pressures in buildings in hilly terrain and surrounding buildings were finished. In the CFD model, surrounding buildings within 500 meters and hilly terrain within 700 meters were established, and total 16 cases including different sensitive wind directions were simulated. The results showed that, because of the complex situation of surrounding hilly terrain and interfered buildings, wind loads in the building group under different direction show opposite characteristics. The speed-up effects by the hilly terrain increased the windward mean pressures when the flow comes from the north, while the interference effects by the surrounding buildings decreased them when the flow comes from the south.


1986 ◽  
Vol 13 (3) ◽  
pp. 375-381
Author(s):  
Ronald A. Macnaughton

This paper contains a wind load and resistance analysis for a type of structure that has frequently failed: partially built houses. The critical component of such structures is identified to be the first-storey shearwalls running across the house. The calculated racking strength of that storey is compared to the wind loading the structure would be expected to resist if it were engineered. Various methods are proposed for builders to provide these structures with more wind resistance during the early stages of construction. Differences between Canadian codes and codes in other jurisdictions with respect to this are pointed out. Key words: wind loads, houses, failure, wind bracing, temporary bracing, shearwalls, fibreboard, sheathing, permanent bracing, racking strength, construction procedures, nailing, building code.


2017 ◽  
Vol 2017 ◽  
pp. 1-19 ◽  
Author(s):  
Nicola Longarini ◽  
Luigi Cabras ◽  
Marco Zucca ◽  
Suvash Chapain ◽  
Aly Mousaad Aly

The behavior of a very slender building is investigated under wind loads, to satisfy both strength and serviceability (comfort) design criteria. To evaluate the wind effects, wind tunnel testing and structural analysis were conducted, by two different procedures: (i) Pressure Integration Method (PIM), with finite element modeling, and (ii) High Frequency Force Balance (HFFB) technique. The results from both approaches are compared with those obtained from Eurocode 1 and the Italian design codes, emphasizing the need to further deepen the understanding of problems related to wind actions on such type of structure with high geometrical slenderness. In order to reduce wind induced effects, structural and damping solutions are proposed and discussed in a comparative study. These solutions include (1) height reduction, (2) steel belts, (3) tuned mass damper, (4) viscous dampers, and (5) orientation change. Each solution is studied in detail, along with its advantages and limitations, and the reductions in the design loads and structural displacements and acceleration are quantified. The study shows the potential of damping enhancement in the building to mitigate vibrations and reduce design loads and hence provide an optimal balance among resilience, serviceability, and sustainability requirements.


2019 ◽  
Vol 15 (4) ◽  
pp. 1-17
Author(s):  
Mihail Iancovici

Abstract The Romanian, as well as other wind design codes for building structures, provides with limited degree of accuracy, the aerodynamic loads distribution on buildings up to 200 meters tall in an equivalent static approach (ESWL). For tall wind-sensitive building structures, especially for those with irregular shapes, most of the codes or standards recommend for design to use pressure data recorded in the wind tunnel. The ESWL approach is however used as reference estimation and structural first phase design. Advances on experimental and computational capabilities, led in the past decade to a significant development of time-domain analysis framework, both for seismic and wind loads. While the major outcome for earthquake engineering practitioners is to select appropriate design input ground motions at a particular site, the wind engineering practitioners are facing numerical difficulties to handle large wind loading durations, especially dealing with nonlinear-induced effects. The paper presents a real-time integrated framework for the analysis and design of tall buildings to wind loads, based on the time-domain analysis tool, as a prerequisite for higher level modules as vulnerability, risk and loss estimation, and optimization analyses.


2014 ◽  
Vol 578-579 ◽  
pp. 1208-1211
Author(s):  
Jian Guo Zhang ◽  
Hui Min Zhuang

In this paper, 2 high-rise building models with ladder and cascade irregularities of elevation were tested in a wind tunnel respectively to measure the mean and fluctuating wind pressure distributions. The mean and RMS (root-mean-square) coefficients of the drag, lift and torsion moment on the measuring layer were obtained from the wind pressures. In the direction which the buildings were positive in the wind, the variation of these above mentioned coefficients with height and the power spectrum densities of the fluctuating wind loads on sudden changed positions were analyzed in detail. Compared with the elevation regular tall building, the wind load characteristics of irregular ones were more complicated.


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