Unformatted text preview: ollowing load:
Concrete strength:
Steel Strength:
Dead Load:
Live Load:
Max Soil Pressure: effective depth “d” is the
distance from top of the
footing to the centroid of
the reinforcing steel ld d Designing Wall Footings: Example
upward soil pressure d 3” cover oneway shear line ld 3” cover FOUNDATION DESIGN  P. RAAB d d
d 14”
#5 bars [8in o.c.] ld ARCH3355  Construction III  Spring 2013 d
d 14”
#5 bars [8in o.c.] ld 3” cover d 14”
#5 bars [8in o.c.] ld FOUNDATION DESIGN  P. RAAB 2 4/25/13 compression in
top of footing d d column
load [P] b distance “d” from the
face of the wall [critical
section for shear] a d/2
e g face of wall [critical
section for moment] f h d
twoway or punching
shear line 3” cover oneway shear line c
tension
reinforcing Designing Wall Footings: Example face of column: [critical
section for moment] development length of
reinforcing steel tension in
bottom of footing Find the required depth, width, and reinforcement for the following load:
Concrete strength:
Steel Strength:
Dead Load:
Live Load:
Max Soil Pressure: f’c = 3000psi,
12”
fy = 60,000psi,
14,000 lb/ft of wall length,
7,000 lb/ft of wall length,
3,500 lb/ft2 12” 36” 5’ below grade #8 bar [1in dia] d d d Step 05: Find the Steel Required: d ld a = Asfy / 0.85fcb [As is unknown à༎ Try a = 1inch] f’c = 3000psi,
fy = 60,000psi,
14,000 lb/ft of wall length,
7,000 lb/ft of wall length,
3,500 lb/ft2 Step 05: Find the Steel Required [continued]:
l See Reference Table for values / spacing of reinforcing bars:
d 12” a = depth of the rectangular stress block, determined by:
compression in
top of footing Concrete strength:
Steel Strength:
Dead Load:
Live Load:
Max Soil Pressure:
d 3” cover
ld As = Mu / [Φfy(d – a/2)] column
load [P] Find the required depth, width, and reinforcement for the following load: 12” d effective depth “d” is the
distance from top of the
footing to the centroid of
the reinforcing steel d Designing Wall Footings: Example
upward soil pres...
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 Spring '08
 Staff
 Retaining wall, footing, Foundation Design, soil pressure, P. RAAB

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