Unformatted text preview: : Find the Longitudinal
Temperature Reinforcement: #5 bars [8in o.c.] 3” cover ld d 14”
#5 bars [8in o.c.] ld Per ACI Code: Steel area must be at least 0.002 times the area of the section
As = 0.002(12in)(14in) = 0.34in2 per linear foot of footing
There are many possible combinations of bar sizes and spacings (refer to table)
à༎ #4 bars at 7in on center
This achieves the steel area of 0.34in2 / linear foot of width à༎ WORKS! Check Actual Length vs. Determined Development Length
36in – 3in = 33in > 15in à༎ Development Length OKAY!
ARCH3355 | Construction III | Spring 2013 FOUNDATION DESIGN | P. RAAB Wall Footing: Details FOUNDATION DESIGN | P. RAAB ARCH3355 | Construction III | Spring 2013 Retaining Walls: Basic Types gravity wall cantilever wall piling wall anchored wall gravity wall:
Depend on mass of their materials [typically stone, concrete or other heavy material] to resist forces using self weight.
Can pivot and topple relatively easily as the internal leverage of the earth pressure is very high. height limited to 10’
Made from an internal stem of steel-reinforced, cast-in-place concrete or mortared masonry. This system uses the
same earth pressure trying to topple it to stabilize itself using a second lever arm.
Using long piles, this wall is fixed by soil on both sides of its lower length. If the piles themselves can resist the bending
forces, this wall can take extremely high loads.
counterfoot h h/3 anchored wall:
This wall keeps itself from toppling by having cables driven into the soil or rock fixed by expanding anchors or
embedded in a “deadman” [which is a weighted anchorage buried within an existing slope]. May also be combined with
other types of walls.
ARCH3355 | Construction III | Spring 2013 FOUNDATION DESIGN | P. RAAB effective depth “d” is t
distance from top of th
footing to the centroid
the reinforcing steel ld tension in
bottom of footing d
d 3” cover FOUNDATION DESIGN | P. RAAB tension
reinforcing 12” d two-way or punching
shear line c upward soil pressure d Designing Wall Footings: Example
ld ARCH3355 | Construction III | Spring 2013 #8 bar [1in dia] d d h one-way shear line 12” 36” 5’ below grade d face of wall [critical
section for moment] f g development length of
reinforcing steel tension in
bottom of footing distance “d” from the
face of the wall [critica
section for shear] a d/2 ld shear line one-way shear line d d column
load [P] d 1...
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- Spring '08
- Retaining wall, footing, Foundation Design, soil pressure, P. RAAB