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):||1 February 2014|
|PDF File Size:||12.79 Mb|
|ePub File Size:||12.78 Mb|
|Price:||Free* [*Free Regsitration Required]|
In response to orders for international standards, it is BSI policy to supply the BSI implementation of those that have been published as British Standards, unless otherwise requested. For this type of roof it is necessary complete roof, e.
The exception to this is the treatment of the load cases involving local drifting of snow, where it is recommended that these are treated as exceptional loads and used in design with reduced safety factors. The type and record length of the ground snow data available and the paucity of observational data on roof snow loads make it extremely difficult to 63399-3 snow load distributions reliably.
The snow loads should be determined according to clause 7. Contact the Information Centre. In the former hs the values should be used directly while in the latter case they should be factored by an appropriate value depending upon whether an ultimate or serviceability limit state is being considered. BS ,Code of practice for dead and imposed loads.
Meteorological Office are as follows. The appropriate drift length and snow load 66399-3 NOTE In determining the upper bound values for these drift coefficient for an abrupt change of height should be loads account has been taken of known cases of excessive, drifting obtained from Figure 6 or from the following in of snow in the UK.
Therefore, it is often necessary to consider several loading situations to ensure that all the critical load effects are determined. The total snow load per metre width in all elsewhere on the roof. This code can be used for design using permissible stresses or partial factors. The appropriate drift length and snow load shape coefficient for an abrupt change of height should be obtained from Figure 6 or from the following in which all parameters are as defined in Figure 6.
For roofs of more than two spans with approximately symmetrical and uniform geometry, b3 should be taken as the horizontal dimension of three roof slopes i. 66399-3 response to orders for international standards, it is BSI policy to supply the BSI implementation of those that have been published as British Standards, 6939-3 otherwise requested. Snow is treated specifically in this code while the minimum imposed roof load value allows for loads resulting from rain, ice and temperature.
For type 1 curved roofs the equivalent slope is the angle between the horizontal and a line drawn from the crown to the eaves. Up to three basic checks are made as follows. In the direction parallel to the obstruction or valley it should be uniform and assumed to extend along the complete length of the obstruction or valley, except where stated otherwise.
This value is assumed to be constant over the complete roof area.
To determine the uniform and asymmetric snow load cases, these structures may be divided into the single-span basic elements considered in 7. Accept and continue Learn more about the cookies we use and how to change your settings. BSLoading for buildings. For asymmetric pitched roofs, each side of the roof should be treated as one half of a corresponding symmetric roof.
The this arises they should be treated as alternatives.
For the redistributed snow load cases the distribution of the snow in the direction parallel to the obstruction is normally assumed to be uniform. Compliance with a British Standard does not of itself confer immunity from legal obligations.
The primary loading conditions to be considered are: It should be assumed to act vertically and refer height of the building. It should also be taken into account in the design of any obstruction on a roof which may prevent snow sliding off the roof. This British Standard applies to:. In some transport of snow from one side of the ridge to the circumstances more 639-93 one of the load cases will other side. This results from transport of snow from one side of the curved roof to the other side.
If permission is granted, the terms may include royalty payments or a licensing agreement.
In general, load cases should be considered to act 7. Use of the uniformly distributed snow loads are subject to an overriding minimum requirement.
Drift length ls1 is the least value of 5h01, b1 and 15 m. Superseded by BS EN NOTE The sopleths in Figure 1 are derived from analysis of data from a limited number of recording stations and therefore unusual local effects may not be included. CP 3, Code of basic data for the design of buildings1. For sites whose altitude is to a horizontal projection of the area of the roof. The snow load on the roof should be considered to be a medium term load for the majority of design in the UK, i.
It is incorporated by Royal Charter. The factor is appropriate for the design of most structures. Care should be taken in the selection of b3 the greater length of building from which snow is available to be blown into the drift. However, one difference is that, in general, the uniform snow load condition and the drift snow load condition are treated as independent load cases. Amendment 2 has been issued to address problems encountered with use.
Click to learn more. British Constructional Steelwork Association Ltd. You may experience issues viewing this site in Internet Explorer 9, 10 or CP 3, Code of basic data for the design of buildings1.
BS _Loading for building-Part3 Imposed roof loads_图文_百度文库
Revisions British Standards are updated by amendment or revision. For these roofs it is a that resulting from a uniformly distributed necessary to consider a single load case resulting layer of snow over the complete roof, likely to from a uniform layer of snow over the complete roof.
In some circumstances more than 63399-3 local drift load case may be applicable for the same location on a roof in which case they should be treated as alternatives. The snow load shape often necessary to consider several loading coefficients do not include any allowances for situations to ensure that all the critical load effects drifting at parapets or other obstructions as these are determined.
For this case, the local drift from 7.