safety factors on buildings

[slippydog]

Hi guys, I'm using british standards and was wondering when you have a dead load (1.4) live laod (1.6) snow load (1.6) and wind load (1.2) do you calculate all of these seperate or is there a combination factor you use, i.e. do you apply a safety factor of 1.2 to them all and not work them out individually with the safety factors mention earlier?!

Cheers

 

[e104909]

You have to read all over again..bs code stated in very clearly

Regards,
E104909

 

[ajh1]

With any load factor type design your safety factor is effectively split into two parts. The load factors as you've noted provide a factor to accommodate a potential overload situation for each load type. In addition there will generally be some sort of resistance factor applied as well that provides a comfort level to accommodate things like misfabrication, miserection, etc. that is likely to vary depending upon the type of construction used (steel, concrete, wood, masonry, etc.). In addition, codes that utilize an importance factor are effectively boosting the safety level by that factor when it is greater than 1.00. The combination of all of those gives the net safety level of the structure.