Wind Loads on Attached Canopies

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Journal of Wind Engineering

and Industrial Aerodynamics 91 (2003) 975994

Wind loads on attached canopies and their effect

on the pressure distribution over arch-roof

industrial buildings

M.J. Palucha

, A.M. Loredo-Souzab,

*, J. Blessmannb

aUniversidade de Passo Fundo, Passo Fundo, RS, BrazilbLaborat !orio de Aerodin #amica das Constru@*oes, Departamento de Engenharia Civil, Universidade Federal do

Rio Grande do Sul, Av. Osvaldo Aranha, 99/305, Porto Alegre, RS 90035-190, Brazil

Abstract

Arch-roof industrial buildings are very wind sensitive. The current aerodynamic coefficients

in wind codes do not contemplate the possibility of existence of canopies attached to the

buildings. This paper presents the results of an investigation on the influence exerted by

canopies on the static wind actions on arch-roof industrial buildings. Six scale models of thesearch-roof buildings were tested, with five types of canopies attached. Three of these canopies

were instrumented and the static wind pressures were measured. The tests were done at the

boundary layer wind tunnel of the Universidade Federal do Rio Grande do Sul. The results

show that the aerodynamic coefficients for the roof are not affected by the canopies, in the case

of axial incidence. However, the influence on the pressure distribution is noticeable for wind

incidence perpendicular to the main axis of the arch roofs and for other incidences as well.

This influence is discussed in the paper. The aerodynamic coefficients for the design of the

arch-roofs, with and without the attached canopies are given. Aerodynamic coefficients for

design of the canopies are also suggested. Furthermore, the paper discusses the relation

between the magnitude of the canopy design forces and the canopy width, as well as therelation between the canopy height location and the height of the building wall. The results

were compared with design recommendations from previous work of Jancauskas and Holmes

(in: US National Conference on Wind Engineering, Proceedings, Texas Tech University,

Lubbock, 1985) and Jancauskas and Eddleston (in: International Conference on Wind

Engineering, Fotodruck J. Mainz, Aachen, 1987).

r 2003 Elsevier Ltd. All rights reserved.

Keywords: Low buildings; Wind tunnel; Codes; Roofs; Canopies

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*Corresponding author. Tel.: +55-51-3316-7146; fax: +55-51-3316-7146.

E-mail addresses:[email protected] (M.J. Paluch), [email protected] (A.M. Loredo-Souza).

0167-6105/03/$ - see front matter r 2003 Elsevier Ltd. All rights reserved.

doi:10.1016/S0167-6105(03)00047-3


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1. Introduction

Industrial buildings are frequently built with metallic members, economically

designed and often they are wind sensitive. The design aerodynamic coefficientsobtained from several Codes[1,2]for arch roofs rarely contemplate the possibility of

any canopies attached to the buildings. These elements are used to provide shelter

over loading bays, shade in tropical areas and to throw rainwater clear of walls. Even

being regularly used, information regarding the effect of canopies on roofs is rarely

found in literature.

This paper presents the results of an investigation on the influence exerted by

canopies on the static wind actions on arch-roof industrial buildings, and on the

static wind actions on the canopies attached to these buildings.

Jancauskas and Holmes [3] investigated the forces exerted by the wind (mean,

RMS and peak value) on canopies attached to low buildings, that is, with a building

wall/canopy height ratio equal or less than 2. Later, Jancauskas and Eddleston [4]

studied the forces exerted by the wind (mean, RMS and peak value) on canopies

attached to tall buildings with a building/canopy height ratio between 1.8 and 36.

In the first study, Jancauskas and Holmes presented the results of an investigation

of the wind loads on canopies attached to buildings with building wall/canopy height

ratios between 1 and 2. For these geometries it was demonstrated that the dominant

net loads (highest peak) for the windward canopy were directed upwards and

happened for a wind direction perpendicular to the windward fa@ade where the

canopy was attached, as shown in Fig. 1a. However, for building height/canopyheight ratios greater than 2, the dominant net loads (highest peak) for the windward

canopy were directed downwards, for the same wind direction as shown in Fig. 1b.

Furthermore, for the case of building height/canopy height ratios greater than 2, the

highest peak upward net load occur for a wind direction parallel to the fa@ade where

the canopy was attached (y 0).

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(a) (b)

Fig. 1. (a,b) Wind loads on canopies fory90 [4].

M.J. Paluch et al. / J. Wind Eng. Ind. Aerodyn. 91 (2003) 975994976


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2. Experimental investigation

2.1. Wind simulation

The tests were performed at the boundary layer wind tunnel of the Universidade

Federal do Rio Grande do Sul[5]with the simulation of the main characteristics of a

suburban natural wind.Fig. 2presents the mean wind velocity profile (p: power law

exponent), local intensity (I1) and macro-scale (L1) of the longitudinal component of

turbulence. The last was estimated from the wave number corresponding to the peak

of the normalized spectrum of the longitudinal component of turbulence.

2.2. Reynolds numbers

Rounded shapes are very Reynolds number (Re) sensitive. To reach reasonable

similarity in static tests it is necessary that model and prototype pressure distribution

be reasonably matched. The Laborat !orio de Aerodin#amica das Constru@ *oes (LAC)

experience shows that for Re above 2 105 the flow around models, with an

adequate roughness, is similar, with tolerable error, to the flow around the prototype

[6]. Sand was used as roughness for the models tested in this work. Admitting that a

value of k=d in the order of 12 103 (k: average height of the sand grains, d:diameter=two times the radius of curvature of the roof) is enough to establish

transcritical conditions in the model, without severe distortions caused by the

roughness itself [7].The models Reynolds number is defined as

Re%Vd

u ; 1

where %Vis the mean wind velocity at the ridge height, d2r(r: radius of curvature

of the circular cylinder), and u the kinematic viscosity of the air.

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Fig. 2. Characteristics of the simulated wind.

M.J. Paluch et al. / J. Wind Eng. Ind. Aerodyn. 91 (2003) 975994 977


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distribution of the pressure taps on the canopies along the x-axis follow the same

pattern as on the roof. In this work, only time mean pressures were measured.

The tests were performed with the wind angle of incidence varying every 15.

However, the models with canopies 13

and 23;which were not instrumented due to their

small size, and were tested only to obtain the effects on the roof for axial wind

incidence (y 0

) and for wind incidence perpendicular to the main axis of the archroofs (y 90).

2.4. Presentation of results

The time mean pressure coefficients, cp; were obtained from the followingexpression:

cp p

q; 2

where p is the effective static pressure at a specific point, given by the differencebetween the static pressure at the point of study and the reference static pressure and

q the reference dynamic pressure (at the top of the models).

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Table 2

Dimensions and proportions of the canopies

Canopy Model

M N O P Q R

1/3 lm/b 1/48

lm 3:3 mm lm/h 1/12 1/6hm/h 1/2 1

ht/hm 2.8 3.6 4.4 1.8 2.6 3.4

2/3 lm/b 1/24

lm 6:6 mm lm/h 1/6 1/3hm/h 1/2 1

ht/hm 2.8 3.6 4.4 1.8 2.6 3.4

1 lm/b 1/16

lm 10mm lm/h 2/8 4/8

hm/h 1/2 1

ht/hm 2.8 3.6 4.4 1.8 2.6 3.4

2 lm/b 2/16

lm 20mm lm/h 4/8 8/8

hm/h 1/2 1

ht/hm 2.8 3.6 4.4 1.8 2.6 3.4

3 lm/b 3/16

lm 30mm lm/h 6/8 12/8hm/h 1/2 1

ht/hm 2.8 3.6 4.4 1.8 2.6 3.4



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Fig. 4. Location of the pressure taps on the roof and canopies.

(a) (b)

Fig. 5. (a,b) Distribution of the pressure taps (a) on the roof, and (b) on the canopies.



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From the cp measured in the roofs, the global force coefficients Cy and Cz were

obtained, by numerical integration, considering as reference area the orthogonal

projection of the roof on a plan perpendicular to the force component in study (see

Fig. 6). The coefficients Cy and Cz were defined as

Cy Fy

q af; 3

Cz Fz

q ab; 4

where Fy and Fz are the components in the y- and z-axis, respectively, of the static

force exerted by the wind on the hole roof.

Although these global force coefficients have some usefulness in the structural

design (reactions in tri-pinned archs, for instance) their main purpose in this study

was to serve as a comparison parameter to study the influence of the presence of

canopies in the global action of the wind over the roofs.

For the design of the main part of the structure the designer needs the pressure

distribution over the whole roof surface. For y 90;the whole arch roof is dividedin six zones and for y 0 the roof is divided into four zones, that is A, B, C and D

(seeFig. 7). For each zone, a spatial average ofcp is presented, that is, cpav :

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Fig. 6. Components of wind forces.

Fig. 7. Zones for application ofcpav in the roofs.



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For the study of roof cladding and of the roofs secondary structure it is necessary

to know the highest suctions that appear in some areas of the roof, in general for

oblique wind incidence. For this, spatial averages of the mean pressure coefficients,

cp; are determined (cpav) over restricted areas located near the edges and roof ridge(areas E, F, G and H ofFig. 8). The largest values of these high suctions do not

occur simultaneously in all the zones identified with the same letters.

For a better visualization of the effects of the canopies on the wind action on the

roofs, as well as, for a best visualization of the loading mechanisms of the canopies,

some transversal profiles of the pressure distribution of cp; for y 90; are

presented.

From the cp measured in the canopies global force coefficients, Cb and Cs; wereobtained (seeFig. 9). The coefficients Cb and Cs were defined as

Cb Fbq a l m

; 5

Cs Fs

q a l m; 6

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Fig. 8. Zones for application ofcpav in the roofs.

Fig. 9. Wind forces on canopy.



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where Fb and Fs are the static forces exerted by the wind on the windward and

leeward canopies, respectively.

For the design of the main structure of the roof, as well as for the design of the

canopies, spatial averages of the mean pressure coefficientscp were determined, thatis, cpav: For y 0

; each canopy was divided into four zones (I, J, K and L zone),with the same size as A, B, C and D zones in the roof (seeFig. 10). Fory 90;thecpav were calculated over the whole canopy surface.

The mean pressure coefficients over the canopies zones, cpav; were defined as

cpav

Pni1c

spic

ipiAi

h i

Af; 7

where cspi; ci

pi are the pressure coefficients obtained at the upper and lower faces of

the canopies, respectively, at point i; for each zone; Ai the influence area of tap orpoint i; Af the area of the zone at study. Fig. 11 indicates the sign conventionadopted for the cpav:

On the other hand, an analysis of the global force coefficients in the canopies, Cb

and Cs; has shown that the largest force upwards or downwards is not alwaysproduced for a wind incidence of 0 and 90. It was then necessary, for design

purposes, to determine cpav for other wind incidences. The cpav for the other

wind incidences were calculated over zones having half the total area of the canopies

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(a) (b)

Fig. 10. (a,b) Zones for thecpav in the canopies.

Fig. 11. Sign convention for the cp av on the canopies.



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(zone T ofFig. 9). However, for design purposes, only cpav maximum (largest value of

downwards mean force) and cpav minimum (largest value of upwards mean force)

registered in each model are of interest. It is worth noting that these largest values of

cpav may be used only for the design of the structural elements of canopies whosedimensions are not larger than half the canopy length.

3. Results and analysis

3.1. Roofs

Figs. 12 and 13 present some of the results obtained from Cy; for the differentangles of incidence of the wind,y:The identification M0 or P0 means that no canopywas attached to models M or P, and M1 to M3 refers to the canopies indicated in

Table 2.Mean values of 100cp (100cpav) are presented inTable 3, fory 90;and in

Table 4for y 0:Values of 100cpav for the determination of the high suction zonesare presented in Table 5. The values of cpav indicated in Tables 35 are the roof

design coefficients proposed here. In Figs. 14 and 15, cp profiles obtained at the

centreline section of the models P and O, respectively, are indicated for y 90:From the figures and tables presented, as well as other results not presented by

space limitations[8], it may be observed that

3.1.1. Force coefficients, Cy

* Model M(seeFig. 12): For a wind incidence from y 45 up toy 90;only thepresence of canopy 3 affects in a noticeable magnitude (100 jDCyjX10) the value

ofCy obtained on the roof without canopy. It may also be said that the presence

of canopy type 3 is favourable in relation to the safety of roof M, since jCymaximumj

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-40

-30

-20

-10

0

10

20

30

0 15 30 45 60 75 90

100Cy

Model: M0

Model: M1

Model: M2

Model: M3

Fig. 12. Force coefficientsCy versus wind angle of incidence for group of models M.



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-20

-10

0

10

20

30

0 15 30 45 60 75 90

100Cy

Model: P0

Model: P1

Model: P2

Model: P3

Fig. 13. Force coefficientCy versus wind angle of incidence for group of models P.

Table 3

Design coefficients for the roofs for y 90

Model Type of canopy 100 cp av for zone

1 2 3 4 5 6

M 0, 1/3, 2/3, 1, 2 70 70 70 30 50 70

3 60 70 70 30 50 70

N Any 10 70 90 40 40 70

O Any 20 60 90 40 40 50

P 0, 1/3, 2/3 40 60 70 30 50 70

1 30 60 70 30 50 70

2 20 60 70 30 50 70

3 20 50 70 30 50 70

Q 0, 1/3, 2/3 0 60 90 50 50 70

1, 2, 3 10 60 90 40 50 70

R 0, 1/3, 2/3, 1, 2 30 60 100 50 50 603 30 50 100 50 50 60

Table 4

Design coefficients for the roofs for y 0

Model Type of

canopy

100cp av for zone Model Type of

canopy

100cp av for zone

A B C D A B C D

M Any 80 20 10 10 P Any 80 20 10 20

N Any 90 30 10 10 Q Any 90 20 10 10

O Any 90 40 10 10 R Any 90 30 20 10



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registered without canopy is reduced in a noticeable magnitude (100j

DCymaximumjX10). In this work, Cymaximum is the coefficient associated to the

static force, following axis y, of greater magnitude.* Model P (see Fig. 13): Only for a wind incidence starting from y 60 for P3,

from y 75 for P2 and for y 90 for P1, the presence of canopies affects in a

noticeable magnitude (100jDCyjX10) the value of Cy obtained on the roofwithout canopy. It may also be said that, although the presence of the canopies is

not favourable in relation to the safety of roof P, since it increases the magnitude

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Table 5

Design coefficients for the roofs for any wind incidence

Model Type of canopy 100cp av for zone

E F G H

M 0 140 130 80 80

1 140 130 80 70

2 140 130 80 70

3 140 130 80 60

N 0, 1, 2 140 120 110

3 150 130 110

O 0, 1 130 130 110

2 130 120 110 3 140 120 110

P Any 150 130 80

Q 0, 1, 2 170 120 110

3 170 140 110

R 0, 1, 2 140 130 120

3 150 140 120

Fig. 14. Centerline profiles of the meancp in models P, for y 90:



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of jCymaximumj registered without canopies, this happens with no noticeable

magnitude (100jDCymaximumjX10).*

Model N, O, Q and R: The force Fy on the roofs is not affected in a noticeablemagnitude by the presence of the canopies.* It should be emphasised that the roof drag (Cy for y 90) was negative for

models M and model P0, what is a feature of arched roofs.

3.1.2. Force coefficients, Cz

* The uplift force Fz on the roofs is not affected in a noticeable magnitude by the

presence of the canopies.

3.1.3. Design coefficients

Wind perpendicular to the main axis of the arch roofs (y 90): The influence of the

windward canopies on the roof, for an angle of incidence of 90, may be explained as

follows: when the canopy is down stream, in the horseshoe vortex, that is, when the

ratioslm=band orhm=ht have lower values, the influence of the canopy on the roof isnegligible (seeTables 13andFig. 15). This condition was registered in models M1,

M2, N1, N2, N3, O1, O2, O3, and in all models with 13

and 23

canopies. However, when

the canopy increases its relative width (lm=b grows with b =constant) and or its

relative height (hm=ht grows with hm =constant), then, as a consequence of thecanopy interference, the streamlines are first constrained and later expanded. From

this streamlines expansion results a velocity reduction, translating in a pressure

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Fig. 15. Centerline profiles of the mean cp in models O, for y 90:



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increase in the roof windward zone (seeTables 13andFig. 14). This condition was

registered in models M3, P1, P2, P3, Q1, Q2, Q3, R1, R2 and R3.

Axial wind incidence (y 0):As expected, the canopies do not alter the cpav (see

Table 4).Local actions:Except roof P, the presence of the canopies with certain proportions

do alter the cpav in some sectors or zones (see Table 5).

3.2. Canopies

Table 6presents the global force coefficients associated to the dominant force. In

this study, dominant force is understood as that which acts on the windward or

leeward canopy corresponding to the larger absolute value among the Cb and theCs

registered for the different angles of incidence of the wind. The same table indicatesthe canopy where the dominant force is acting, the respective angle of incidence and

the dominant force direction given by the sign of the force coefficients Cb or Cs (see

Fig. 9). Mean values of 100cp (100cpav) are presented inTable 7, fory 90;and in

Table 8 for y 0: The maximum mean values of 100cpav (cpav maximum andcpav minimum) for zones T of Fig. 9 are presented in Table 9. The values of cpavindicated inTables 79are the canopies design coefficients proposed here.

From the figures and tables presented, as well as from other results shown

elsewhere[8], it may be pointed out that:

Global actioncoefficients Cb and Cs: In all models, the dominant force is directed

upwards (seeTable 6).The windward loading mechanism over the canopy indicated in Fig. 1a, by

Jancauskas and Holmes[3]and Jancauskas and Eddleston[4], was clearly detected in

models M3, P1, P2, P3, Q2 and Q3 (seeFig. 14). At these models the dominant force

is produced on the windward canopy, for a wind incidence between 75 and 90.

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Table 6

Dominant forces (seeFig. 9)

Model M1 M2 M3 N1 N2 N3

100 Cb or Cs 17 17 17 17 16 9Canopy Leeward Leeward Windward Leeward Leeward Leeward

y 30 45 75 60 60 6075

Model O1 O2 O3 P1 P2 P3

100 Cb or Cs 17 16 17 80 74 73

Canopy Leeward Leeward Leeward Windward Windward Windward

y 4560 4560 60 90 90 90

Model Q1 Q2 Q3 R1 R2 R3

100 Cb or Cs 24 38 45 25 21 24Canopy Windward Windward Windward Leeward Leeward Windward

y 6090 75 90 4560 60 75



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Negative pressures were registered on the upper surface of the windward canopy for

y 90 (at least for part of it).

In models M1, M2, N1, N2, N3, O1, O2, O3, R1 and R2, where clearly the loading

mechanism of Fig. 1a was not detected, the dominant force is produced in the

leeward canopy, for a wind incidence between 30 and 75.

In models Q1 and R3, the upward dominant force is produced in the windwardcanopy, for a wind incidence between 75 and 90, although no suctions were

detected at the upper surface of the canopy.

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Table 7

Design coefficients for the canopies for y 90

Model Type of

canopy

100cp av for canopy at Model Type of

canopy

100cp av for canopy at

Windward Leeward Windward Leeward

M 1 0 0 P 1 80 0

2 10 0 2 70 0

3 10 0 3 70 0

N 1 10 10 Q 1 20 20

2 0 10 2 30 0

3 0 0 3 50 0

O 1 10 10 R 1 0 10

2 10 0 2 10 103 0 10 3 10 10

Table 8

Design coefficients for the canopies for y 0

Model Type of

canopy

100cp av for zones Model Type of

canopy

100cp av for zones

I J K L I J K L

M 1 10 0 0 0 P 1 10 0 0 0

2 20 0 0 0 2 0 0 0 0

3 10 10 10 0 3 10 0 0 0

N 1 10 0 0 0 Q 1 0 10 0 0

2 20 0 10 0 2 20 10 10 0

3 0 10 10 0 3 10 10 10 0

O 1 10 10 0 0 R 1 20 10 10 0

2 20 0 10 0 2 20 10 10 0

3 10 10 10 10 3 20 10 0 0



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The windward loading mechanism over the canopy indicated inFig. 1bwas clearly

detected in models N1, N2, O1, O2 and O3 (see Fig. 15). In these models, the

maximum downwards force is produced in the windward canopy, for wind between

75 and 90. However, this mechanism, which is dependent of the building/canopy

height ratio, was not able of imposing the dominant load.A direct relationship between the magnitude of the dominant force andhm=hwasdetected. With respect to the relation magnitude of the dominant force/canopy width

(lm) it may be said: (a) In the groups of models M, O and R, there is no variation

withlm;(b) in the groups of models N and P an inverse relation was detected; (c) in

models Q a direct relation was detected.

Wind perpendicular to the main axis of the arch roofs (y 90): The loading

mechanisms on the canopies, as well as the influence of the windward canopies on

the roofs, for a wind incidence of 90, may be interpreted in the following way (see

Figs. 14 and 15): When the canopy is in the path of the down flow, in the horseshoe

vortex (Fig. 1b), that is, when the relationslm=band orhm=ht have lower values theinfluence of the canopies on the roof is negligible. This condition was registered in

models M1, M2, N1, N2, N3, O1, O2 and O3. Besides, it is under these conditions

that the loading mechanism indicated in Fig. 1b is most intensely produced, its

efficiency depending on the ratio hm=ht: However, when the canopy increases itsrelative width (lm=b increases with b = constant) and or relative height (hm=hmincreases withhm= constant), then, as a consequence of the canopy interference, the

streamlines are first constrained and later expanded. From this streamlines

expansion results a velocity reduction, and a consequent increase in windward

pressures. This condition was registered in models Q1, R1, R2 and R3. Finally, for

certain values of the relations lm=b and hm=ht; the loading mechanism indicated inFig. 1ais produced, where the before mentioned effects are more pronounced. This

condition was registered in models M3, P1, P2, P3, Q2 and Q3.

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Table 9

Design coefficients for the canopies for any wind incidence

Model Type of

canopy

For zone T Model Type of

canopy

For zone T

100cp av minimum 100cp av maximum 100cp av minimum 100cp av maximum

M 1 20 0 P 1 80 0

2 20 0 2 70 10

3 20 0 3 70 10

N 1 20 10 Q 1 30 0

2 20 0 2 40 10

3 10 10 3 50 10

O 1 20 10 R 1 30 0

2 20 10 2 30 03 20 10 3 30 10



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* In the identified Fig. 17 and Table 11 the full-scale dimensions andconfigurations of the models tested by Jancauskas and Eddleston [4] are

indicated.

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Fig. 16. The attached canopy configuration.

Table 10

Measured uplift forces on attached canopies for a wind direction ofy 0

Run h (mm) hc (mm) Wc (mm) Ic (mm) hc/h hc/wc UPLIFT

C%Fz CF0ZC#Fz

JCUNQ

1 84 84 64 96 1.0 1.31 +0.85 0.29 +2.28

2 84 84 36 96 1.0 2.33 +1.34 0.48 +3.58

3 84 84 36 192 1.0 2.33 +1.21 0.42 +3.16

4 84 84 52 96 1.0 1.62 +1.03 0.36 +2.71

5 84 84 96 96 1.0 0.88 +0.65 0.23 +1.69

6 63 63 64 96 1.0 0.98 +0.64 0.24 +1.88

7 42 42 64 96 1.0 0.66 +0.50 0.19 +1.43

8 84 63 64 96 0.75 0.98 +0.26 0.16 +1.05

9 84 42 64 96 0.50 0.66 0.01 0.14 +0.51

CSIRO

10 84 84 64 96 1.0 1.31 +0.87 0.30 +2.3711 84 84 32 96 1.0 2.63 +1.35 0.47 +3.64

12 42 42 32 96 1.0 1.31 +0.79 0.31 +2.46

13 84 63 64 96 0.75 0.98 +0.38 0.20 +1.31

14 84 63 32 96 0.75 1.97 +0.37 0.26 +1.64

15 84 42 64 96 0.50 0.66 0.01 0.16 +0.66

16 84 42 32 96 0.50 1.31 0.21 0.20 +0.56

17 42 21 32 96 0.50 0.66 +0.04 0.19 +0.92



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* In the following table some comparisons among aerodynamic coefficients fromthe work by Jancauskas and Holmes[3]and from Paluch[8](the proposed paper)

are presented (with exception of C%FZ; the notation is that used in the work byPaluch [8]) (see Table 12). Despite the differences in the models tested in both

works, the results obtained in the windward canopies for y 90 (according to

our convention) are practically the same (see column cpav C%FZ). However,

in the case of models N2 and N3 the dominant force, according to our

convention, is produced in the leeward canopy (Cs) for a wind incidence

y 60 75 (seeTable 6). It should be observed that this situation was registered

in those models in which the geometries (relations lm=b and hm=ht with

sufficiently lower values) are associated to a transition in the loading mechanismsin the windward canopies for y 90; from the mechanism of Fig. 1a to themechanism ofFig. 1b.

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Fig. 17. Nomenclature.

Table 11

Summary of configurations investigated

Parameter Basic configuration Range investigated

Building

Height (h) 150 m 9180 m

Breadth (b) 40 m 2080 m

Depth (d) 40 m Not varied

Canopy

Height (hc) 5 m 2.510 m

Width (wc) 5 m 2.510 m

Thickness (tc) 0.8 m Not varied

Upstream terrain Open rural Open rural, suburban

Upstream building None Height (hu): 1075 m, separation (x): 1540 m



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References

[1] Associa@*ao Brasileira de Normas T!ecnicas, ABNT. NBR-6123For@as devidas ao vento em

edifica@*oes, Rio de Janeiro, 1988, 88pp.

[2] National Building Code of Canada, National Research Council of Canada, Associate Committee onthe National Building Code, Ottawa, NRCC No. 23178, 1990.

[3] Jancauskas, E., Holmes, J., Wind loads on attached canopies, in: US National Conference on Wind

Engineering, Proceedings... Texas Tech University, Lubbock, 1985.

[4] E. Jancauskas, J. Eddleston, Wind loads on canopies at the base of tall buildings, in: Seventh

International Conference on Wind Engineering, ...Aachen, Preprints, Fotodruck J. Mainz, Aachen,

1987.

[5] J. Blessmann, The boundary layer wind tunnel of the UFRGS, J. Wind Eng. Ind. Aerodyn.

Amsterdam 10 (1982) 231248.

[6] J. Blessmann, Wind on isolated and adjacent industrial pavillion curved roofs. In: Jubileum

Conference on Wind Effects on Buildings and Structures, Porto Alegre, Proceedings... A.A. Balkema,

Rotterdam, 1998, pp. 137171.

[7] J.L.D. Ribeiro, Efeitos da rugosidade superficial sobre as press *oes m!edias e flutuantes em cilindros

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ARTICLE IN PRESS

Table 12

Run ab h lm/b h/hm ht/hm cp av C%FZa Csb

CSIRO 17 11 0.20 0.15 2 3.3 +0.04 N2 21 0.25 0.13 2 3.6 0 +0.16

N3 21 0.25 0.19 2 3.6 0 +0.09

Run ab h lm/b h/hm ht/hm cp av C%FZa Cbb

CSIRO 12 11 0.20 0.15 1 1.7 +0.79

P2 21 0.12 0.13 1 1.8 +0.70 +0.74

P3 21 0.12 0.19 1 1.8 +0.70 +0.73

a cpav : design mean coefficients for the windward canopies for y 90; see Table 7; C%FZ: Mean

coefficient associated with the mean net vertical force on the windward canopy, for y 90 (according to

our convention), seeTable 10; cpav andC%FZ

present opposite sign conventions.bCb or Cs: global force coefficients associated to the dominant force, see Table 6 (in our study,

dominant force is understood as that which acts on the windward or leeward canopy corresponding to the

larger absolute value among theCb and theCsregistered for the different angles of incidence of the wind);

C%FZ;Cb and Cspresent the same sign conventions.


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Wind Loads on Attached Canopies

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