Cantilever/Gravity Walls Cantilever/Gravity Walls

Bar lists and estimates from standard design sheet

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Cantilever/Gravity WallsCantilever/Gravity WallsCantilever walls have footings

forward/back of the wall (wall is essentially a cantilevered structure

Gravity walls have no footings

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http://content.answers.com/main/content/img/McGrawHill/atchitecture/f0169-02.png

http://www.gravesconcrete.com/allaboutretainingwalls.htm

PrecastPrecast

3http://www.humes.com.au/ProdsServices/PrecastConcrete/PC_StorageWalls.shtml

Standard Design Sheets-Standard Design Sheets-CIP CIP Cantilever/Gravity Wall Standard

Note: Not to be used for design!!!! Handouts are old, rescinded standard sheets given solely for the educational purpose of looking at details and deriving bar lists.

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Some assumptions used for Some assumptions used for std. designstd. design Unit wt of earth – 120 pcf Unit wt of concrete – 150 pcf Active earth pressure of soil behind

wall – 30 psf (level surcharge) A one-ft depth of surcharge was

applied above the toe of the footing. Earth fill behind the wall was

assumed w/ the top of finished grade 0.75 feet below wall coping

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All retaining walls are All retaining walls are structures -----possible structures -----possible failure modesfailure modesOverturningSlidingEccentricity (footing can lift)Bearing pressure (footing can

burrow into the soil)Rotational stabilitySettling

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Retaining Wall FailuresRetaining Wall Failureshttp://www.youtube.com/watch?v

=EXjVXaqWDLo

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ExampleExampleGiven:Stem 8’Min. Allowable soil pressure=1

Ton/sq ftDesign friction coefficient= 0.5Wall is 40’ long

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ExampleExampleFrom Design Std:Footing width: 5’-2”Toe Projection: 1’-8”T Bars #5@18”H Bars #5@18”D Bars #5@18”B Bars #5@18”Concrete Unit Quantity: 0.88 cy/lf

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Drawing/Bar MarksDrawing/Bar MarksBar marks different than shown

on standard drawingsE indicates epoxy coated bars

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Cantilever Wall Bar List

Mark Size No Type Length (ft)Length

(in)Total

Length (ft) Wt/FTTotal

Weight (lb)

5WHFE 5 9 Straight 39 6 355.50 1.044 371

5WVFE 5 21 Straight 7 9 162.75 1.044 170

S-Bar 5WVR 5 28 Straight 7 9 217.00 1.044 227

5WHR 5 5 Straight 39 6 197.50 1.044 206

D-Bar 5WDR 5 28 Curved 5 4 149.33 1.044 156

5WFL 5 8 Straight 39 6 316.00 1.044 330

H-Bar 5WFTT 5 28 Straight 4 8 130.67 1.044 136

T-Bar 5WFTB 5 28 Straight 4 8 130.67 1.044 136

Data/Assumptions From Table Plain Rebar 1191 lbStem Height 8 ft Foot. Width 5'-2" Epoxy Rebar 541 lbSoil Pressure 1 T/sf Toe Proj. 1'-8" Conc Volume 35 cyCoef of friction 0.5 T-bars 5@18"Wall Length 40 ft H-bars 5@18" Total Price $8,626

D-Bars 5@18" Price/LF $216Conc Price $200 /cy S-Bars 5@18"Rebar $0.90 /lb Conc 0.88 cy/ftEpoxy rebar $0.95 /lb

Assume 3" End CoverAssume 3" cover on footingAssume 2" cover on stem