The assessment of full-scale experimental methods for measuring wind effects on low-rise buildings

7/27/2019 The assessment of full-scale experimental methods for measuring wind effects on low-rise buildings

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THE ASSESSMENT OF FULL-SCALE EXPERIMENTAL

METHODS FOR MEASURING WIND EFFECTS ON LOW RISE

BUILDINGS

B. ParmentierBelgian Building Research Institute, Limelette, Belgium

R. HoxeySilsoe Research Institute, Silsoe, United Kingdom

J-M. Buchlinvon Karman Institute, Rhode St Gense, Belgium

P. Corierivon Karman Institute, Rhode St Gense, Belgium

ABSTRACT: This paper deals with the assessment of full-scale experimental methods for measuring wind ef-fects on low rise buildings. It has been elaborated in the framework of the working group 3 Large scale facili-ties and full-scale measurement of the COST action C14 The impact of Wind and Storm on the City Life andBuilt Environment.

1 INTRODUCTION

After experiencing huge wind storms during the 90s (1990-1995-1999) a lot of research pro-

grams were launched worldwide to investigate the reasons why so many roofs encountered

severe damages like truss-wall failures or more frequently roof elements removals. This last

issue seems to be less important for the security aspects but gives the insurance companies

some nightmares when seeing the global bill. This problem will be more and more concern-

ing because there is a general agreement about the increase of potential wind storms due to

the global warming of the planet. G. Berz from Munich Reinsurance Company commented

The insurance industry must prepare for an unexpected explosion in windstorm losses [3].

Actually, it is more the number of damage occurrences during a storm event than the ex-penses by occurrence that can drastically increase the (repairing) costs. This is a problem

wind engineering can try to solve by different approaches:

Numerical simulations CFD simulations Full-scale tests Wind tunnel tests

This paper will address the use of full-scale tests and the potential assessment of these by

means of model scale tests with focus on low-rise buildings.

2 FULL-SCALE TESTS

Historically, full-scale (F-S) tests were used to provide reference values for wind action on

low-rise buildings and were intended to be used for the validation of model-scale (M-S) tests

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in wind-tunnels. The need of codification has contributed to the development of extensive

measurements programs of which the Aylesbury experiments were the first most publicized

results [10]. The building used was a two-story house. The dimensions were 7x13.3 m and

the eave height was 5 m. The pitch of the roof could be in the range 5-45. This research

program has produced different sets of external pressure coefficients for a geometrically well-

defined structure according to the wind direction or more meaningfully the wind angle of at-

tack (AOA).

In the last decades different studies were conducted in the same field. The most used full-scale data were the ones from Texas Tech Building (low-rise building with flat roof -in USA)

and from the Silsoe Structures Building (low-rise building, cube, mast -in UK). More re-

cently on this topic, a new facility has been erected by the Belgian Building Research Institute

in Limelette (BE) to assess the validity of model-scale results achieved in the wind-tunnel

from the von Karman Institute (BE) for a duo-pitched roof of a low-rise building but other fa-

cilities (with their own specifications) have already been used around the world (short term

projects).

The implementation of full-scale tests is often not easy due to the costs and the time which

is needed to obtain a large number of validated data but it seems that full-scale tests are neces-

sary for wind tunnel assessment. The parameters that can be important for the achievement of

full-scale tests can be summarized by the following issues :1. terrain description (topography, wind speed profile, turbulence intensity profile,)

2. building description (geometry, orientation from North, building materials,)

3. hardware acquisition system description (pressure taps, pressure tubing, reference pres-

sure, filters, pressure and meteorological transducers, )

4. software acquisition system description (sampling frequency, sampling duration, sampling

condition, )

5. validation procedure description (quality control, stationarity tests, )

6. analysis of the results

2.1 Terrain description

The terrain where the building is erected can be described by topographical parameters and

meteorological data can be used to characterize it e.g. by a wind speed profile and a turbu-

lence intensity profile. The wind velocity profile can be obtained by using averaged wind

speeds at different heights. Once this has been achieved the comparison with theoretical pro-

files can be done with the assumption of a profile law (logarithmical or power). This also will

be used to control the wind profile in the wind tunnel.

In general a meteorological mast positioned upstream the building (away from the influ-

ence of the building generated turbulence) can be used with different anemometers mounted

at different heights. In most cases 3-cup anemometers are used but sonic anemometers are

more and more often used with the advantage of giving not only wind speed along the longi-

tudinal direction but also along the lateral and vertical directions. This can be useful to de-termine the turbulence intensity profile in the three components by using the relations given in

Eq. 1 and also the Reynolds stress. Recent developments have outlined the importance of the

knowledge of these different turbulence intensities to understand relative discrepancies be-

tween model-scale and full-scale measurements [see 4].

mean

rms

U

U

uI = ; meanrms

U

V

vI = ; meanrms

U

W

wI = (1)where :

Iu, Iv and Iw are the longitudinal, lateral and vertical turbulence intensity, respectively U, V and W are the wind speed components in the longitudinal, lateral and vertical direc-

tions, respectively with suffix expressing the statistical output

In order to analyze the pressures and use the dimensionless parameters Cp (pressure coef-

ficient) one anemometer should be placed at the building ridge height on the meteorological

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mast. This is needed to provide a reference dynamic wind pressure at the building ridge

height, the most commonly used in the codes.

The measurement of the wind profile can give the roughness parameter by comparing with

theoretical values from the logarithmic profile (Eq. 2) or with a power law profile (Eq. 3).

The former should preferably be used because it derives from theory [9]. Nevertheless, the

power law is frequently used because its mathematical expression is easy to use. On the other

hand, the classification of terrains according to visual observation can be made and hence the

parameter z0 or describing the roughness category can be assumed [8].

H/Href= (V/Vref) (2)

V = 2.5u*.ln((z-d)/z0) (3)

Obviously it is difficult to change the roughness category of a terrain used in a full-scale

study while it is easy to do that in wind tunnel. So, it is difficult to introduce this parameter in

a full-scale study on a short term period. For long term research the only way to study the ef-

fect of different terrain roughnesses is to benefit from a heterogeneous site with different

roughness conditions depending on the wind direction. Despite the fact that wind comes sta-

tistically from particular orientations depending on the country it is hoped that a large numberof records can involve significantly different wind directions. This is illustrated in Figure 1.

Another characteristic of some full-scale facilities is their possible rotation around their cen-

ter. This allows comparisons to be made between model-scale and full-scale measurements

for all wind angles of attack whatever the most common wind directions.

It is also known that the roughness parameter or the turbulence intensity can have some

variation in the short term. Tieleman [33] reported Iu variations from 17% to 27% on the same

day for the same direction during full-scale tests. This can be caused by convective condi-

tions during a summer day. Consequently it is necessary to always keep in mind the atmos-

pherical parameters when comparing full-scale and model-scale results and ensure at full-

scale the atmospheric stability is recorded

0%

10%

20%

30%

40%

50%

60%

120 150 180 210 240 270 300

Wind direction from North []

Iu

3m/s


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action of this internal pressure the actual net pressure on the roof can be calculated. If the lo-

cal roughness of the roof elements is supposed to be playing an important role square flat

plate with a tapping hole inside can be superimposed [25].

Of course the geometry of the building should be described by its length, span and height

(at eave or ridge). The influence of these parameters have been pointed out by Hoxey et al

[17]. Nevertheless, more work should be done on this topic to be easily incorporated in the

standards. The slope of the roof is another important parameter. Stathopoulos summarized

some conclusions in a paper on the influence of this parameter for transverse wind [31]. Thetype of the roof can also be an important factor as it is known that hipped roofs are more fa-

vorable in terms of mean pressure coefficients than gable roofs [20].

Last but not least, specific details of the construction can also influence some results (see

4).

Silsoe Experimental Building

TTU Experimental Building BBRI Experimental Building

Figure 2: Full-scale experimental buildings.

2.3 Hardware acquisition system

Pressure measurements are often carried out by a pneumatic system with particular specifica-

tions [9] to prevent wrong measurements. Different options exist to measure the pressures

depending on the implementation of the system: each pressure tap can be associated with a

pressure transducer or different pressure taps can be collected by a pneumatic system to apressure transducer which measures each channel by using a scannivalve. The pneumatic sys-

tem can be long (e.g. 30 m) but care should be taken to limit the resonance effects and control

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the response of the system (limiting amplification and phase delay for high acquisition fre-

quencies). With the other system, each tapping point can be associated with its own trans-

ducer [22]. This limits the problems arising from the tubing response (spectrum fall-off after

typically 2-3 hertz) but the costs are obviously more important. In order to limit the problems

associated with the tubing response different systems with restrictors can be used [16].

Typical (internal) diameters of the PVC tubing system reaches 8 mm. The effect of the tap

diameter has been investigated by Peterka et al [24] by comparing taps of 80 mm diameter

pneumatically averaged full-scale pressures with taps of 8 mm diameter in full-scale and 0.8mm taps diameter of model-scale tests (1:100 model). The result was that separated flows

with no vortex present (a much larger flow feature) showed no dependence of the relative tap

size while in areas of intense vortex activity the 8 mm full-scale tap peak negative pressure

was almost 2 times the pressure of the model while the 80 mm measurement was roughly

50% larger. Peterka et alconclude that some effects of viscous dissipation is present in the

model due to the tap size which is at the edge of the viscous dissipation range. But it seemed

difficult to incorporate some clear conclusion of this into design aspects.

In general the pressure transducers are differential. Hence, a reference pressure is needed

for the first input to the transducer while the other input will be the surface pressure. Differ-

ent static pressure probes can be used upstream of the building to provide this reference. In

some cases, a wooden box in the ground can also provide a relatively good reference pressure.In this case this pressure is assumed to be barometric and relatively stable. In some full-scale

studies, an insulated box has been used [12] inside high buildings. The absence of climatic

changes in this box provide the stability which is needed.

Three-way valves can be used to calibrate (zero-drifting) the transducers in order to limit

the variations coming from temperature effects or other climatic changes that can influence

the measurements on long term.

2.4 Software acquisition system

It is well known that full-scale measurements are time-consuming studies. Among the rea-

sons for that are: The wind speed at the ridge height must be beyond a given limit (V lim) to reduce noise in-terferences due to electronical measurement devices and to produce relevant wind effects

on the structure. So the implementation of this is a wind speed limit in the software acqui-

sition program. In function of this factor and the site where the structure is erected the

number of records will be more or less important. Values of Vlim beyond 7 m/s at the eave

or ridge height are often used [6][16][24][22] on the mean wind speed during a last speci-

fied period ( 1 to 5 min, ). Nevertheless, the influence of a reduced wind speed limit has

been evaluated through an analysis of the Limelette results (see Figure 3). This last figure

shows that the influence of the speed limit (preferably beyond 5m/s) is inexistent for mean

pressure coefficients even in the separated and vortex flow regions while its effect on peak

values is not well known.

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Figure 3: External mean pressure coefficient for a roof corner tap. From the aboveleft sub-figure the data between wind speed limits V lim,inf and Vlim,sup are added tofinish at the below right sub-figure.

The time duration of the records should be representative of the observed wind event. It ismore clarified by the analysis of the spectral characteristics of the wind. As reported by

A.G. Davenport, the record duration should be in the spectral gap (between 10 and 1h)

to be independent of the macro and the micro-meteorological effects (see Figure 4).

Figure 4: Along-wind spectrum recorded in Brooklyn after Davenport in [9].

The acquisition frequency should also be well designed. In most cases an acquisition fre-quency between 10 and 40 samples per second will be reasonable to establish spectra and

to be sure the pressure peaks are not underestimated. Filtering the data can be performed

in order to reduce the factor measure/noise. For example, the data obtained on WERFL

[32] were acquired at 40Hz and low-pass filtered at 8Hz. It is linked to the frequency re-

sponse of the pneumatic acquisition system (see above).

Full-scale studies have been reported on other kinds of structures (tall buildings, bridges

decks, bridge cables, sun-shading elements or free-standing walls) but are not treated in this

paper.

2.5 Validation procedure

Full-scale tests are difficult to carry out because of different multiple problems. Among them

are:

Time costs of the study (Vlim) Difficulties in controlling all the acquisition tools due to the large number of instruments

(if each tap is connected with its own transducer)

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Problems due to weather and other conditions (rain, dust, insects, rabbits !!!)Due to all these potential problems it is useful to carry out a validation procedure for each

run in order to assess the validity of this run. In the tests achieved by BBRI in Limelette the

validation process is based on :

1 Storage of date/hour/Vmean/Vdirection in a log file before the recording begins for each run

2 Visual check of time history of each tap for the first and the last run of a windy event (be-

yond Vlim)3 If uncertainty on the results of a specific tap exists perform different comparisons and

controls:

3.1 Comparison with the closest tap(s) results

3.2 Comparison with symmetrical tap(s) results

3.3 Comparison with the tap located under the outside skin if this one exists

3.4 Spectral signals of the tap results

3.5 Visual verification of the hardware system for the tap incriminated

4 Memorize the defective taps and take it into account for the analysis (e.g. spatial interpo-

lation)

In some full-scale studies a further step in the validation of the results was the control of

the stationarity of the runs. As described in Bendat and Piersol [2], this procedure checks thestability of the wind speed and wind direction during the run. It is thought that a run for

which the average wind speed grows continuously could give some discrepancies between

peak values. However the effects of the stationarity of the runs is somewhat confusing. The

trends of the data collected by Peterka et al(see Figure 5) do not seem different if the sta-

tionnary runs are also used

Figure 5: Full-scale results in a gable roof vortex region after Peterka et al[24].

2.6 Analysis procedure

The methods used for the analysis of the runs is very dependent on what is required . In gen-

eral, the basis is the computation of the pressure coefficients (Cp). The values used to calcu-

late these coefficients must be explicitly known (dynamic wind pressure and reference pres-

sure).

The most common theory in the codes is the quasi-steady theory which assess that the fluc-

tuations of the load on the structure exactly follows the variations of the incoming wind. This

is expressed into the equivalent steady gust model (Gu only depends on the variations of theflow). In some codes, a factor (K=Kx.Ky) is used to take the effects of the building generated

turbulence into account depending on the location on the building (Kx) and the averaged zone

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(Ky) on which the load is applied. In this theory, the load duration in included in the gust fac-

torGu also sometimes called SG.

2

2

3max,

min .... Umeanmean

s

mean GKCpU

UKCpCp =

= (4)

The peak factor approach can also be used:

meanu CpgICp )21(min += (5)

In this theory the gfactor (peak factor) also depends on the location on the building but

also incorporates the gust duration. The factorsKi andgcan be calibrated by means of tests

(full-scale or model-scale, see 4 for results).

Mean values are the most important parameters because these are the main basis of the

codes [9]. Besides this parameter the peak values are necessary to study the statistical aspects

of the wind event on the structure due to the turbulence (of the incoming flow or generated by

the building itself) through the validation of the theory. It is important here to correctly

mention the load duration which is used to specify extreme values: is it instantaneous or aver-

aged on 1s, 3s or more.

The different parameters that can be treated by full-scale tests can be:

Influence of the geometry of the building (L:H:B, roof slope, ) Influence of building details (sharp or curved eave, gutter, ) Influence of the averaging zone for the pressure measurements Influence of the averaging time on the extreme values (Gu andgfactors) Comparisons between full-scale and model-scale measurements and theory validation

3 MODEL-SCALE TESTS

In order to validate the full-scale results for codification purposes a lot of different research

programs dealing with model-scale (M-S) tests have been conducted worldwide. One of thefirst programs involved in a comparative study was the Aylesbury Comparative Experi-

ment (ACE) , during the 1980s. The goal of this study was to check full-scale results but

also to compare the results of 15 different wind tunnels around the world. Analysis of the

mean and the extreme data were incorporated into a report that showed the variability be-

tween labs could be very high. So, it was obviously important to investigate all the parame-

ters that could give different results in modeling low-rise structures.

3.1 Important parameters to model

3.1.1 Geometry

Global geometry of the building (at scale), the relaxation of scale can be performed undercertain conditions [30].

Details of the building (parapets, gutters,) Details of the topography details (e.g. modeling of the upstream hedges was crucial for the

Aylebury wind tunnel simulation after Surry [32]).

3.1.2 Flow Modeling

As it was mentioned in the description of full-scale tests the turbulence intensity is a very im-

portant parameter in order to study peak pressures on structures. The aim of modelling is to

obtain dynamic similarity. The single most important parameter when modelling structures in

the Atmospheric Boundary Layer (ABL) is the ratio of the structure height (H) to the aerody-namic roughness of the terrain (z0) included in the logarithmic profile of the mean wind

speed. This factor (Je=H/z0) is now called the Jensens number after the work performed by

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M. Jensen (1967) which demonstrated its influence. Cook [9] mentioned that a mismatch of

Je by a factor 2 to 3 can be acceptable. Usually the reproduction of the Iu profile coupled with

the reproduction of the Vmean profile (Figure 6) is the basis of the model-scale testing. This

reproduction is, for practical aspects caused by the reduced section of the wind-tunnels, lim-

ited to a certain height. It is only important to verify the reproduction of the profiles up to a

height that is still sensitive for the building (3H).

0

5

10

15

20

25

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.1 1.2

V/Vref [ / ]

y

[m]

F-S tests

M-S tests

Power-law (a=0.26)

BBRI building ridge height

Figure 6: Model-scale building from the von

Karman Institute (VKI).

Figure 7: Wind velocity profile of the BBRI site in

Limelette compared with wind tunnel simulation

from the Von Karman Institute (VKI).

Another factor which is also required to be the same to compare M-S tests with F-S tests is

the Strouhal number (St=nD/V). The inverse of this parameter is often used in the analysis of

spectra and called the reduced frequency. Similarity of St is needed to reproduce the duration

of the gust loads. An example of the application can be found in different papers related to

model-scale studies. For example Ham and Bienkiewicz [16] assume the ratio Vmean,M-

S/Vmean,FS=1 at ridge height for the measured data. The geometrical scale of the model was

1:50. So it derives from the Strouhal number match that:

The frequency scale should be 50:1. A model-scale acquisition frequency (fs,MS) of1000Hz was chosen to correspond to a full-scale acquisition frequency (fs,FS) of 20Hz

The time scale will be 1:50. Hence, a recording duration of TS,MS 18 s was used in themodel-scale testing to be compared with TS,FS of 15mins full-scale measurements

In most cases the high fs,MS introduces some distortion in the signal response of the trans-

ducers due to resonance effects of the pneumatic system. These systems are consequently

coupled with restrictors and low-pass filtering. In the study of Ham and Bienkiewicz [16], the

restrictor provided a signal reduction of 3dB at 230Hz. The cut-off frequency of the filters

was 200Hz.The similitude of the Reynolds number (Re=VD/) can not be performed in wind-tunnel

with geometrical scales smaller than 1:10 due to large Re observed in full-scale. Nevertheless

it is agreed that it is sufficient to ensure Re is large enough (>10e4-10e5) in the model-scale

testing for inertia forces to dominate when sharp-edged structures are studied [15].

4 COMPARISONS BETWEEN F-S AND M-S TESTS EXAMPLES

At the present time the following issues have been pointed out by M-S tests, F-S tests and F-

S/M-S comparisons:

There is a critical wind angle of attack for mean pressures depending on the geometry of

the structure and the roof slope [4][15][22]. An example is given in Figure 8 for which thecomparison between von Karman (VKI) model-scale and full-scale (BBRI) is satisfactory.

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On this figure, the existence of a critical AOA at about 20 (from the ridge) is clear for both

experiments.

Figure 8: Full/Model-scale comparison of worst mean positive and negative externalpressure coefficients for a duo-pitched roof of 30 in Limelette. Full-scale results aregiven on the left while VKI model-scale measures are given on the right.

The CPmean and CPrms and CPmin tend to be reduced by the extent of the averaging zone.

The simulation of large obstacles is difficult due to blockage effects in the wind-tunnel

For some cases the influence of the gust duration (T) can be described by an exponential

law as it can be seen found in [34] in function of the tap location.

The probability density function of the peak factor or the pressure fluctuations for signals

in roof corner locations is negatively skewed from the Gaussian form [16][5].

The effect of the longitudinal turbulence intensity is negligible for mean pressure coeffi-

cients [34][25].

Quasi-steady theory can give good comparisons for high negative peak pressures because

the main fluctuations arise from the wind for roofs steeper than 4:12. For the other cases the

building generated turbulence caused some discrepancies between theory and model-scaletests [34][25][32][24][4][27].

Pressures near curved eaves of low-rise buildings can be correctly modelled while errors

are present for sharp eaves due to fluctuations associated with the building edges [25]. The

same conclusion can be given for the simulation of transverse wind AOAs vs. oblique wind

AOAs [32].

The influence of parapets has been reviewed by different researchers. Some conclusions

indicate that a small ratio of the parapet height to the building height can cause suction in-

crease and parapets on only one side can give higher mean and peak local pressures that those

coming from perimetrical parapets.

Different conclusions regarding to the influence of longitudinal turbulence on the peak

pressures is confusing : while Case and Isyumov [7] notices that a building experiences lowersuction loads (up to 30%) from open country to suburban exposure (and higher loads associ-

ated with positive pressures), Bienkienwicz and Sun [4] mention higher negative peak loads

due to higher longitudinal turbulence intensity (5%) with 74% increase of the integral length

scale.

It has also been found that a lateral turbulence intensity increase can cause higher peak

pressures. This was the principal assumption for explaining discrepancies between model-

scale and full-scale results by Tieleman et al[33].

Peak factors from [24] were found to be in the range [5-5.5] for zones of flow separation

and in the range [3.5-4] for intense vortex formation regions. On the other hand values of

about 6 and 7 were found by Uematsu and Isyumov [34] for roofs and walls, respectively. A

value of 3.5 is used in Eurocode 1 [8]. In this field of pressure coefficients, it is also found

that the KL factor (equivalent steady gust model) is underestimated for cladding fasteners de-

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sign [14] for small areas but the total calculated pressure could be well evaluated when using

the calculated load with the KA factor [14].

Some model-scale tests showed that resistance of loose-laid roof pavers increase when the

ratio of the space between to the space underneath increases [14].

The geometrical ratio L:B is important to describe the pressure coefficients for low-rise

buildings [17]. The only use of the ratio H:B can be simplest.

Multiple spans decrease the worst mean pressure coefficients on the roof [28].

CPmin can be averaged on multiple runs in order to estimate statistically stable estimates offull-scale intervals (e.g. average of 5 runs of 16s is used by Stathopoulos and Saathof in [ 28]).

This can be performed for taps associated with large peaks. And from [33] it seems clear that

discrepancy between M-S and F-S peaks can not be attributed to the definition of these peaks

but comes more reasonably from inadequate duplication of certain aspects of the flow simula-

tion.

The wind effect on double skin structures has been treated in different papers. One of

them from [11] concentrates research on facades (climatic facades, PER or BVR facades)

with parametric wind-tunnel tests and full-scale validation. The influence of the geometry of

the building, details of construction (edge sealing) and the permeability of the outer skin have

been assessed. The conclusion of the model-scale study was e.g. that increasing the gap width

could cause more critical mean net pressure coefficient and that edge sealing decrease signifi-cantly the mean net pressure coefficient. The comparisons with full-scale tests were satisfac-

tory but were better for edge sealing than without it. The reason for that was assumed to be a

minor difference in gap flow resistance between these two cases. A last example of a research

programme dealing with model scale and full-scale measurements comparisons was presented

in [23] for shingles. The goal of the research programme was to elaborate a wind load uplift

model to provide more accurate design rules for shingles. One particular aspect of this re-

search was the implementation of roof wind speed measurements (Uroof just above the pres-

sure taps) as reference in place of the wind speed at ridge height upstream of the building

(Uref). This was used in the model base on the quasi-steady theory and proposed for the de-

termination of the peak net pressures (DPpeak) for shingles. This model (equivalent gust factor

approach) is given in Eq. 6:

meanrefmean

refmean

roofDCpU

U

UDP 2 ,

2

,

max,

min2

1.

= => mean

refmean

roofDCp

U

UDCp

2

,

max,

min

= (6)

The factors (Umax,roof/Umean,ref) and DCpmean were measured in wind tunnel to give a design

value of DCppeak of -2.5. The minimum value in full-scale was found to be -1.6. Thus the

measured peaks are enveloped by the prediction model. However the model does not reflect

the correct theory even for cases when the main wind flow is not up the roof.

Finallyn an example of comparison between model and full-scale measurements respec-

tively from VKI and BBRI are presented in Figure 9. These figure compares the Cp measured

on the edge of the building as a function of the angle of attack of the wind. This type of results

shows a relatively good agreement between field tests and model-scale measurements.

These last results will be soon proposed for publication.

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Figure 9: Comparison between model-scale and full-scale tests for edge roof region

of a low rise building ; external mean pressure coefficient as function of the angle ofattack.

The development of powerful techniques (hardware and software) will give the researchers

the opportunity to expect more accurate data in the future and a lot of tools to analyze these

(statistical analysis, graphical outputs,). The goal is to better understand phenomena thatcan explain discrepancies between model-scale and full-scale measurements.

5 AKNOWLEDGEMENTS

BBRI gratefully acknowledges the support received from the Belgian Federal Government

(IWONL/IRSIA and Ministry of Economic Affairs) under grants CI 1/4-8827/208 and CC

CIF-407. The different research programs carried out by SRI were supported by the Ministry

of Agriculture, Fisheries and Food.

6 LITERATURE

Notation : JWEIA=Journal ofWindEngineering andIndustrialAerodynamics

1. Baskaran A. and Stathopoulos T., Roof corner wind loads and parapet configurations,

JWEIA, (1988).

2. Bendat J.S. and Piersol A.G., Random data Analysis and measurements procedures,

John Wiley and sons, New-York, 1986.

3. Berz G.and Conrad K., Winds of change. The insurance industry must prepare for an

unexpected explosion in windstorm losses, Review, N.6 (1993), 32-35 .

4. Bienkiewicz B. and Sun Y., Local wind loading on the roof of a low-rise building,

JWEIA, No.45 (1992), 11-24.

5. Bienkiewicz B. and Sun Y., Wind loading and resistance of loose-laid roof paver sys-

tems, JWEIA, No.72 (1997), 401-410.6. Bienkiewicz B. and Sun Y., Wind loading on the roof of a low-rise building, JWEIA,

No.45 (1992), 11-24.

7. Case P.C. and Isyumov N., Wind loads on low buildings with 4:12 gable roofs in open

country and suburban exposures, JWEIA, No.77&78 (1998), 107-118.

8. CEN,Eurocode 1 Actions on structures. Part 1.4 : General Actions Wind actions, Fi-

nal draft, CEN, Brussels, August 2001.

9. Cook N.J., The designers guide to wind loading of building structures. Part 2 : Static

structures, Butterworths, Garston, 1990.

10. Eaton K.J. and Mayne J.R., The measurement of wind pressures on two-storey houses at

Aylesbury, JWEIA, Vol. 1,No.1 (1975), 67-109.

11. Gerhardt and Janser, Wind loads on wind permeable facades, JWEIA, No.53 (1994).12. Geurts C.P.W., Wind induced pressures on building facades, Ph. D. Thesis, Eindhoven

University of Technology, 1997.

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The assessment of full-scale experimental methods for measuring wind effects on low-rise buildings

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