Usage if Seismic Importance factor for lethal vessel as per ASCE 05

[ting123]

Dear Eng. Members,

My query is "what seismic importance factor shall be used while designing a lethal vessel(column)ground supported. If client specification says that the occupancy category is III then as per ASCE- Table 11-5-1 importance factor is 1.25. Does OC III includes hazardous material?. Furthermore as per para 13.1.1 it should be 1.5 for component containing hazardous material. Is it acceptable to use 1.25 saying that requirement of chapter 13 are not applicable as it is for "non structural components" and not "building structures" or " non building structures"

I express my sincere thanks to all members in advance for your valuable help.

 

[Duwe6]

Vessels are not 'occupancies'. Design to the Seismic Zone that the vessel will be used in. And the 1.5 multiplier for 'hazardous materials' is a minimum. You are working with LETHAL, not just hazardous materials, but they will be contained in a vessel. As the engineer-of-record, you are required to assure that the column will be stable in an earthquake, and not sway enough to make the attached piping fail. Not easy. Might try checking with some nuke engineers; they have been designing earthquake-safe piping-plus-vessel systems for 30+ years.