Purchase your copy of BS as a PDF download or hard copy directly from the official BSI Shop. All BSI British Standards available. The use of BS part 2:wind loads, for design of temporary structures (English ) Wind loading: a practical guide to BS , wind loads on buildings. PROFESSIONAL. Welcome. IP51S0LUTIONS. Thank you and welcome to ‘ BS Wind Loading – Practical Design, an IStructE seminar presented by.
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Annex B informative Derivation of extreme wind information B.
External pressure coefficients for flat roofs with edge parapets are given in Table 8, dependent upon the ratio of the height h of the parapet, defined in Figure 17a63999-2 the scaling length b.
When necessary, interpolation should be used between the orthogonal wind directions to obtain values for the other wind directions. When the procedure of 2. NOTE Wind load on a partially completed structure may be critical and will be dependent on the method and sequence of construction.
Careers and apprenticeships Equal opportunities Vacancies Apprenticeships. Currently, the network numbers about stations and the main archive comprises hourly mean wind speeds and wind directions, together with details of the maximum gust each hour.
When symmetry is used to reduce the number of orthogonal load cases, both opposing wind directions, e. When considering low rise buildings which are close to other tall buildings the rules for effective height will not necessarily lead to conservative values and specialist advice should be sought. gs
For the preparation of the basic wind speed map given in Figure 6, a superior technique involving the maximum wind speed during every period of windy weather or storm was used. NOTE 2 Where both positive and negative values are given both values should be considered. If the loads produced by the standard method are critical to the design, the use of the hybrid combination given in 3.
BS Loading for buildings. Part 2 Wind loads | José García –
Standards are also available from the BSI website at http: For external walls, provided there are no dominant openings, the internal pressure coefficient Cpi should be taken as either —0.
Steep-pitched surfaces attached to the top of vertical walls are better interpreted as pitched roofs, falling under the provisions of 3. The frictional drag coefficient should be assumed to act over all zone C of such walls, with values as given in Table 6. NOTE If there are fascias at the eaves or verges see 2. The maximum net pressure coefficient Cp across internal walls should be taken as 0. Zones of external pressure coefficient are defined in Figure Mean hourly wind speeds.
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BS – Loading for buildings. Code of practice for wind loads
It should also be noted that adjustments to partial b on loading may be necessary depending on: In these cases two sets of values are given and they should be treated as separate load cases.
For polygonal buildings this may be conservatively based on the concept of the smallest enclosing rectangle. The ba of the annual risk is sometimes referred to as the return period and is best interpreted as the mean interval between recurrences when averaged over a very long period.
Larger overhangs should be treated as open-sided buildings, with internal pressure coefficients determined using the provisions of 2. Reference heights Hr are defined with the pressure coefficient data for each form of building.
Values of Sh should be derived for each wind direction considered and used in conjunction with the corresponding direction factor Sd. Zones A and B should be defined, measuring their width from the upwind edge of the wall.
The reference height Hr is the height above ground of the top of the wall. Vertical or inclined sections may be taken as being divided into parts of length at least twice the crosswind breadth, L U 2B, and the reference height Hr should be taken as the height above ground of the top of each part.
Part 2 now withdrawn which incorporated the considerable advances made and experience gained in wind engineering since that time. Users of British Standards should make sure that they possess the latest amendments or editions. NOTE 5 For pitched roofs with curved or mansard eaves, the values in this table may be compared with the appropriate values in Table 9, Table 10 or Table 11 and the least negative values used.
Whereas at higher risks, for example for frequent service conditions, the q model predicts higher wind speeds than before. The effective wind speed is a gust wind speed the map for the UK. Part 2 Wind loads. Accordingly no interpolation between the three terrain categories is permitted in this part. However, the hourly mean basic wind speed is subsequently converted into a gust wind speed for use in design by a gust peak factor which takes account of gust duration time, height of structure above ground and the size of the structure.
NOTE The standard pressure coefficients may be used for buildings and elements of generally similar shape.
The zones start from the edge of the flat part of the roof as defined in Figure 17b. NOTE 4 The design risk for bridges, corresponding to a mean recurrence interval of years. For the single wall, use pressure coefficients for walls given in Table Regrettably, indication of copyright fee is not available.
Corrected and reprinted June NOTE 3 Where both positive and negative values are given, both values should be considered.
Table 17 — Internal pressure coefficients Cpi for buildings with dominant openings Ratio of dominant opening area to sum of remaining Cpi openings and distributed porosities 2 0. This applies to the sea, but also to inland lakes which 6939-2 large enough and close enough to affect the wind speed at the site.
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It was found that the rate of convergence of storm maxima to the FT1 model was faster for the q model than the vs model. Buildings falling outside these limits should be assessed using established dynamic methods. In reading the value of s from these figures, the location with respect to the crest of the feature is scaled to the lengths of the upwind LU or downwind LD slopes as follows: Kh and Kb are parameters depending on the building height and location and on the form of construction of the building see C.
For all other wings the overall crosswind breadth of the building should be used.