Date of issue August September May Indicated by a sideline in the margin Comments BS The subsequent calculations make use of some or all of the following documents: BS BS BS BS BS Find the most up-to-date version of BS at Engineering
|Published (Last):||28 July 2014|
|PDF File Size:||8.55 Mb|
|ePub File Size:||5.35 Mb|
|Price:||Free* [*Free Regsitration Required]|
Where simultaneous drifts in several valleys of a multispan roof are being considered in the design of a structure as a whole, a maximum limit on the amount of drifted snow on the roof 3699-3 be applied. BS ,Code of practice for dead and imposed loads. The primary loading conditions to be considered are: This standard has been updated see copyright date and may have had amendments incorporated. To provide for these situations, if 66399-3 are likely to occur and if other information is not available, a load case should be considered comprising the minimum imposed uniformly distributed load according to clause 699-3 on any portion of the roof area and zero load on the remainder of the area.
For the redistributed snow load cases the distribution of the snow in the direction parallel to the obstruction is normally assumed to be uniform. The full list of organizations that have taken part in the work of the Technical Committee is given on the Inside front 639-3. BSLoading for buildings. BRE DigestLoads on roofs from snow drifting against vertical obstructions and in valleys2.
This check takes the general form of Meteorological Office, limiting the snow load shape coefficient to: The value for the snow load shape coefficient should be obtained from Figure 4 a.
BS _Loading for building-Part3 Imposed roof loads_图文_百度文库
Snow loads 5 Snow load on the roof 4 6 Snow load on the ground 4 7 Snow load shape coefficients 6 8 Snow sliding down roofs 9 Appendix A Annual probabilities 63399-3 exceedance different from 0. We would be grateful if anyone finding an inaccuracy or ambiguity while using this British Standard would inform the Secretary of the technical committee responsible, the identity of which can be found on the inside front cover.
Users of British Standards sb responsible for their correct application. For this case the variation in the 639-93 parallel to the obstruction is non-uniform. The snow load on the roof calculated using the coefficients in this subclause should be assumed to be variably distributed. However, as an approximate rule, it is only necessary to consider nearby structures when they are less than 1.
This results from a appropriate local drift loads as given 7. British Constructional Steelwork Association Ltd. Ensure use of the most current version of this document by searching British Standards Online at bsonline. General 1 Scope This Part of BS gives minimum imposed roof loads for use in designing buildings and building components which are to be constructed and used in the UK and the Channel Islands.
Click to learn more. They are corrected for an assumed ground level datum of m above mean sea level and have an annual probability of exceedance of 0.
The treatment of snow drifting against obstructions in section two is similar to that given in BRE Digestissued in October 63993, but now withdrawn. Revisions British Standards are updated by amendment or revision. If permission is granted, the terms may include royalty payments or a licensing agreement.
The drifts which occur at local projections and obstructions affect a relatively small area of roof only.
This results from a uniform layer of snow over the complete roof. Snow load shape coefficient? Use of the uniformly distributed snow loads are subject to an overriding minimum requirement. Abstract This part of BS specifies minimum imposed roof loads for use in designing buildings and building components which are to be constructed and used in the UK and the Channel 639-3.
Appendix B explains the logical process behind the calculations. Code of practice for imposed roof loads Licensed Copy: Snow loads 5 Snow load on the roof 6. For a complex roof value for the snow load shape coefficient 639-3 be shape there may be several load cases associated obtained from Figure 3 a ; this value is assumed to with condition b.
This subclause applies where there is an abrupt change of height greater than 1 m, except that relatively slender obstructions e. The values are bz as lines of equal load intensity isopleths on the map in Figure 1.
Users of British Standards should make sure that they possess the latest amendments or editions. For details of these and other benefits contact Membership Administration. For roofs with no access, the minimum imposed roof load value includes an allowance for repair and maintenance work.