10 ft existing masonry wall sdc E 2007 cbc

[bdruehl]

bdruehl (Civil/Environme)
1 Jun 09 19:21
ah... more "as-builts"!!! everyone's favorite!!! CBC 2007

10 foot existing masonry wall fully grouted with half inspection evidence and half contractor statement to come up with a confident #4 @ 24" vert and horiz full height/length, no openings. Client wants to put up a small 20x15 garage with this wall as one side.

Siesmic zone E...
so "special reinforced masonry" is required by code. Well, im sure there are no 180 hooks and whatever else is required to classify it as "special reinforced"... (gettin back into reading that part of code now) Building inspector requiring a "letter" that it complies with 2007 CBC...

comments... how many of you would require a tear down of the wall?

 

[bdruehl]

or just put up 2x4 wall right next to it and shear it and call it good eh? make "sure" the new wall can handle the masonry wall racking against it during seismic... seems silly, but guess it will work.. thoughts!?

 

[msquared48]

In that you are making this a "holy" wall, who is to argue that it is not "special"? Problem solved.

Mike McCann
MMC Engineering

 

[InDepth]

Why don't you perform some destructive testing to verify the details in a certain section of the wall. You may also find out the strength properties, which may be larger than what the specifications called for.

Or shotcrete a concrete facing against it.....

 

[bdruehl]

sure, but at some point the testing becomes more expensive and time consumin for everyone, that the original idea of a 2x4 wall on the inside, no matter how silly, may be a better solution?

talked to a few engineers, one said that the hook requrement could be assumed to be imitated by a develpment length of the horizontals, so if i take a development lenght off each side of the wall (full length no openings) i still have plenty of "shear" left...

and that perpendicular attachement required by asce 12.11.2 is rather large 1300# at each truss?!

 

[bdruehl]

blah.,... ever try to get expoxy into top of block wall at 1300 lbs perp to wall! ha~! just so happens that the truss on this side (already delivered onsite) has a 2 ft high kicker wall... ever try to get a plate loaded perpendicular to a masonry wall at 650# a foot with 5/8 bolts! ha!

i think ive just bunred through the cost of a 2x4 wall already!