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CMU Masonry Fence - Dooley Wall 1

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AELLC

Structural
Mar 4, 2011
1,339
Does anyone have a detail of this? I lost mine - it is 4" unreinforced CMU, fence 6" high, spanning horizontally to pilasters that have a couple of #3 or #4 rebars and trench footing. I don't recall pilaster spacing, footing size, etc.
 
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That's it - thanks Bridgebuster!
 
AELLC:
Except, that’s not the way the fence builders do it unless you watch then very closely. And, there seems to be a few variations on the theme depending on exactly where you are located and who the block supplier is. The fence I inspected was in the Phoenix area and was dry laid, with no mortared horiz. joints or horiz. joint reinforcing. The 4" wall blocks were keyed together at the horiz. jnts. and just butted together at the vert. jnts., maybe there was a keying arrangement there too, laid in running bond. The pilaster blks. were dry laid, and core filled, but not always full to the top blk. Then there was a 2" cap blk. on top of the pilaster. The vert. rebars in the pilaster cores seemed to be a pretty random detail, and the stl. down into the ftg. was more likely than not just stabbed into the ftg. The ftgs. were about 12" x 8" deep under the wall, hand dug, with no rebar that I could see; and the pilaster ftgs. were just 16-24" +/- drilled to pretty random depths and belled out a bit at the top to make them look larger in dia. All-in-all, it was a pretty shaky proposition. They were still standing, leaning in some locations, but had suffered some serious washouts in the foundations. Now, what to do to fix them?
 
I am looking at the walls at my subdivision - the horizontal joints are all mortared, the 4" CMU keys into the H-pilasters, and for some reason the 3rd course down from the top has mortared end joints - maybe it's a bond beam. All the walls appear plumb but there is some distress because the soil here seems fairly expansive.

 
There are many variations on the "Dooley Walls" depending on the application and locality. Usually the local municipality may have drawings if they are just privacy walls.

Most are built using 4" walls spanning between vertical pilasters that carry the wind loads into the ground. Since there is little vertical load from the 4" wall, it is not necessary to have a strip footing under the wall portion, but it is common for finishing/appearance purposes.

Some of the walls were built in place with some bond beams and mortared to the pilasters, while others were built elsewhere with every few courses a bond beam a bond beam and the panels were set between/into the pilasters.

In a couple of areas, some walls (usually 6" or 8" thick) were built in a factory by a block laying machine and erected/set at the site. - Every few days, I drive past some DOT sound barrier walls (12'-16' high).

Dick

Engineer and international traveler interested in construction techniques, problems and proper design.
 
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