ICC 500-214 - Missile Impact Loading?

[sticksandtriangles]

With the recent 2015 IBC adoption in the state I work in, all buildings that fall into risk category IV (firestation in my case) need to be designed to have a storm shelter in accordance with ICC 500-214.

I have begun to do some research on this document and wanted to know how people handled duct penetrations through their wall/roof. Some preliminary research on this website did not lead much that is fruitful either.
Based on table 305.1.1 a 15 lbs 2x4 needs to hit a vertical surface at 100mph and a horizontal surface a 67mph for a 250mph design wind speed.

Is there any easy way to convert this momentum (mass times velocity) into a static load? How do I know what to design for based on this information?
I have some sample details that shows a 1/4" plate steel plate that gets anchored on (3) sides with epoxy anchors to a concrete wall and wanted to verify a detail like this works. The (3) sided connection allows for the duct penetration to enter through the wall and then make a 90 degree turn thru the unanchored side. Someone in my office mentioned remembering FEMA pre-rated assemblies that can work without testing with test results conducted by Texas Tech. From reviewing these documents, no testing was specifically complied on penetrations (just wall assemblies).

Also, my mechanical engineer needs a louver to meet some of the ventilation requirements within ICC 500. Do you typically ask the mechanical person to provide a rated louver that is missile impact tested? Do I need to provide a layer of protection in front of the louver?

Thanks in advance for the help,
S&T

 

[WARose]

See this thread:

http://www.eng-tips.com/viewthread.cfm?qid=426448

 

[sticksandtriangles]

my google skills...

 

[RPMG]

I'm not familiar ICC 500, but Force * time = mass * velocity, which isn't useful. That leaves tested assemblies only.

I would assume that ducts have to pass through a bar mesh and that the louver has to be caged. An alternative may be running ducts underground and using a series of vents. But I've never come across this.

 

[thaidavid40]

One way to effectively get around all of these design obstacles is to have two rated wall assemblies parallel to each other, to create a rated chase. Then you take the ducts in and out of the protected space along different lines. Having them out of alignment provides a backup barrier to a missile entering through the exterior opening. Similar to what is often done for the doors and entryways on these shelters - a winding path works wonders (and saves money).
Davbe

Thaidavid