Conflict in Risk Category Table
Conflict in Risk Category Table
(OP)
We are working on a high rise hotel with a meeting room space hosting more than 300 people; in our opinion, the structure should be categorized as II. FBC 2010 Risk Category Table 1604.5 clearly states that Risk Cat III is meant for 'structures whose primary occupancy is public assembly', in which the hotel is not. IBC 2012 clarifies 'primary occupancy' as 'the portion of the building housing the public assembly occupancy is more than 50% of the total building area' [IBC 2012 pg. 16-10]. We don't think it's logical to punish the whole tower just based on 1 single space of meeting room.
What is your thoughts and experience in this?
Thank you for your input.
What is your thoughts and experience in this?
Thank you for your input.






RE: Conflict in Risk Category Table
RE: Conflict in Risk Category Table
Codes set minimum standards, and it seems to me that in this case the higher standard should be applied.
Doug Jenkins
Interactive Design Services
http://newtonexcelbach.wordpress.com/
RE: Conflict in Risk Category Table
However, if you read the commentary of ASCE 7-10, it suggests: "A rational basis should be used to determine the risk category for structural design, which is primarily based on the number of persons whose lives would be endangered or whose welfare would be affected in the event of failure. Figure C1-1 illustrates this concept. "Lives at risk" pertains to the number of people at serious risk of life loss given a structural failure."
It then shows Figure C1-1 with a cutoff between II and III buildings at about 300 persons.
This implies that despite the rigid interpretation of "primary occupancy is public assembly" your big hotel would have lots of people in it at any given time and a structural collapse would affect many lives - suggesting a III is more appropriate.
I think I would tend to use II but would think that getting buy in from the city or owner would be needed.
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RE: Conflict in Risk Category Table
RE: Conflict in Risk Category Table
Wow, there's a lot of room for mischievous interpretation in that statement. Just about any sizable building in an urban environment could be said to meet that criteria. All the more reason to get a ruling on it, in writing, from the building official, as Flight7 advised.
I guess we're all Category III now. Will anyone raise me to Cat. IV?
RE: Conflict in Risk Category Table
And the IBC would or could overrule the ASCE 7 table that in my view is so general to be useless.
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RE: Conflict in Risk Category Table
There would , however, have enormous implications on the precast garage lateral design.