Safety Factor for ASET

[Apollo_SG]

Hi all,

I am doing a Project involving evacuation where we would typically adopt  RSET < 2 ASET as standard. Does anyone know the bibilography or reference for such "factor of safety"?  The best I've come across so far is a reference to works by Jonathan Sime but I've not been able to obtain details of the papers itself to comment if it was indeed relevant.

Apart from the Project, I'm quite concerned that the Authorities here in my country is asking ASET to be 3 times of RSET on a particular project and the RSET to be structured for last man out of the building, nevermind the exit staircases and down 4 flights of steps. I ended up with ASET being 90 minutes for the 4-storey building, which was like..... (censored) incredible.

In some papers, I've seen the meaning of "Place of Safety" stretched to "Place of relative Safety" or "Place of comparative safety" meaning the exit stairs or Area of Refuge, as well as "Place of Ultimate Safety" meaning the external.

Appreciate your feedback on this.

[wee brian]

I am not aware of any standard factor of safety. This is usually a matter of judgement for the particular building. A lot will depend on you confidence with the models/fomula that are used to caclulate the two values.

[Apollo_SG]

Hi, thanks for replying. Ive managed to traced a reference to AH Buchanan from U of Catebury. Factor of 2 is for persons who are ambulant and awake. Higher value needs to be prescribe for young and elderly.

[wee brian]

Am I right in thinking you're in NZ?

Such aprescriptive approach wouldn't normally be used in the UK.

[Apollo_SG]

ah no... I better zip up. the internet can be a fatal distraction if I mention unfavorable things about the Authority here. I won't want the ghost of the past to catch up with me, in the forseeable or unforseeable future.