Underground Structures
Underground Structures
(OP)
I am looking for a reference book for design of underground structures. I am looking at a decant structure that will eventually be 50' tall. The dimensions are 6'square.
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RE: Underground Structures
RE: Underground Structures
RE: Underground Structures
RE: Underground Structures
RE: Underground Structures
The good news is that with 18 inch thick walls, you can use a lot less steel.
RE: Underground Structures
RE: Underground Structures
RE: Underground Structures
If you use the table values for 0.5 single wall you will be overly conservative and end up with a very thick wall with lots of rebar because you are assuming your horizontal wall span will be 40'*0.5=20'
You need to look at 1' wide strips at desired locations and determine the uniform load on your horizontal span. If you look at Case 3 tables with fixed base and walls with b/a=0.5 you will see that the maximum bending moment My occurs at the corners at about 0.3a so to be conservative you could take a 1' strip at 0.25a or 0.75*40'=30' from the top.
Personally with a 6' wall span you might consider the walls as hinged, i.e. simply supported and design for My+ and Vu but with a 6' span. At 90psf/ft depth and 30' you will have a uniform load of 2700 lbs/ft. Mw = wl^2/8 yields 12.15 ft kips, Mu = 1.3*1.7*Mw = 26.8 ft kips and Vu = 1.7*w*l/2 = 13.8 kips It looks like 16" walls with #6 horiz @8" ctrs or 18" wall with #6 horis @12" ctrs would work.
You can step your wall thickness down to 12" as they build the structure in the future but no less than 12" and not less than #5's at 12" ctrs in any direction.
RE: Underground Structures
RE: Underground Structures