ACI appendix D and pre-engineered metal bldg pedestals 3

[braves25]

When it comes to the design of pre-engineered metal building foundations, I find that app. D is causing me grief!!

How do y'all handle the uplift forces and the horizontal forces transferred from the anchor bolts into a concrete pedestal without having the pedestal be very large? For one case (at braced frames where I have a large horizontal shear perp. to the main frame column) combined with uplift, I find it almost impossible to use pedestals. AM I missing something? Thanks!

 

[BUGGAR]

Long ago I used to design pedestals for power poles on concrete pedestals subject to forces from every direction. There were ASCE guidelines for this but you'll have to search the web because I just don't remember.

ASCE Design Guide 8?? Not sure, but it covered this very well and at least represents a national consensus.

Bob

 

[WARose]

Kind of interesting that this conversation is going on while there is another thread about shear friction reinforcement. So what is everyone’s view on load path (with regards to shear)? Say you’ve gotten it into the pedestal with a strut and tie model but you’ve still got to get it from the pedestal to the footing. And if your pier isn’t tall enough you cannot do shear friction properly (see the other thread)…….then what? Run the anchors into the footing? Do the anchors themselves do the job shear friction was supposed to do?

I know how I’ve handled it in the past…..just curious for opinions.

 

[slickdeals]

http://www.bechtel.com/assets/files/TechPapers/design-of-anchor-reinforcement.pdf

 

[MJB315]

How are you holding down that 56.1 kips of uplift? Are you able to grab 56.1/0.6 kips worth of stuff?

"We shape our buildings, thereafter they shape us." -WSC

 

[msquared48]

15 yards of concrete should do it...


Mike McCann, PE, SE (WA)