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does equipment meet seismic requirements

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发表于 2009-9-8 19:15:02 | 显示全部楼层 |阅读模式
does equipment meet seismic requirements
dear everyone,
i work for a company that is installing some new electrical power backup equipment.
i need to make sure it meets the seismic requirements as set forth by the project engineer.  (i am in facilities)
these are the guidelines for the building:
a.seismic-restraint loading:
1.siteclass as defined in the ncsbc:  d.
2.assigned seismic use group or building category as defined in the ncsbc: i.
a.component importance factor:  1.0.
b.component response modification factor:  1.25 (lighting fixtures), 2.5 (equipment), and 3.5 (conduit).
c.component amplification factor:  1.0.
3.design spectral response acceleration at short periods(0.2 second):  0.346.
4.design spectral response acceleration at 1.0-second period:  0.179.
5.seismic design category:  c.
and this is what the equipment manufacturer has provided:
lateral design seismic force at center of gravity of cabinet is 1.5g.
vertical design seismic force at center of gravity of cabinet is 0.75g.
where,z = 1.0
i = 1.0
k1 = 2.5
k2 = 2.0
k0 = 0.3
how can i prove/disprove the equipment meets the requirements?
thank you!
check out our whitepaper library.
the manufacturer of the equipment is responsible for meeting this design criteria. the equipment manufacturers in turn usually subcontract this out to an engineer.
they aren't being the most cooperative.  but no one at my company (including me) knows if the equipment meets or doesn't meet.
i was hoping to figure it out, regardless if the manufacturer goes to a 3rd party engineer....
thanks!
you (or the manufacturer) will need to do stress analysis in order to determine if the equipment can withstand an earthquake. this involves quite a bit of work. this is what i do at my current job. if you want, you can contact my employer: www.thevmcgroup.com
well i think the manufacturer has done the test, and they said horizontally it can tolerate 1.5g of acceleration and vertically it can tolerate 0.75g.. does this make sense?
i'm not sure of your jurisdiction, but the current version of the international building code (typically in the usa) requires manufacturer's to have a 3rd party review the results of analysis or physical tests and then issue certifications. the certification consists of paperwork followed up with a certification label. the certification documents state the "g" levels that the equipment can withstand. my employer is a typical 3rd party. unless you have certification documents from an authorized 3rd party, you have no way of knowing for certain if the equipment meets the earthquake criteria. i would suggest that you obtain these certification documents from the equipment manufacturer. if they can't provide them, then the equipment was not really certified and may not hold up in an earthquake.
under the assumption that the project is in the united states, under the 2006 international building code as adopted and modified by a local jurisdiction:
refer to sections 13.2.1 and 13.2.2 in asce 7-05.
most seismic qualifications that i've seen for electrical components are by "shake table" testing.  i don't know how you could prove by analysis that an electrical component will function during/after an earthquake.
this is a huge issue and will be be more important as more equipment is installed to the 2003 and 2006 ibc and ca converts to 2006 ibc.  manufacturer's are not used to this and are not supplying the right paperwork/analysis.  you need to educate them, show them that this is the law and once they convert, they'll be good to go on other projects.
if you don't stand your ground, you're just deferring their day of reckoning to some time in the future and another engineer to be the hard guy.  and don't do their work for them.  if they say the equipment has been tested to 1.5g (h) and .75g (v), then make them provide results in a format that follows the new i-codes.

u.s. army corp of engineers document ufc3-310-04 appendix f, pages f-28 thru f-77 has an example report prepared by a licensed engineer and peer reviewed by a third party engineer.  2006 ibc and asce7-05 do not clearly describe in detail what constitutes an evidence of compliance.  the us ace document is the only one with a sample report and one prepared similar to this may be submitted to the ahj for approval.
yes, this is a huge issue and many manufacturers will have difficulty getting their products certified in time.
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