Factors of safety
Safety factors provide security against collapse and allow for unavoidable differences between assumed and actual structural behaviour.
When sizing individual elements there is an obvious need for a factor of safety. Apart from providing a degree of security to the building user and the public, there are a number of uncertainties associated with detailed structural design including:
- simplifications in representing the structure for analysis
- accidental overloading of the structure
- material properties which may differ from those specified
- dimensional differences from those those assumed or specified
- loss of material due to corrosion.
