Soil Group Symbol = ML, inorganic silt, fine sand
Safe Load bearing capacity = 3 tons per square foot
Footing Loads
X1 = 14,737 pounds per foot, bearing area = 14,737 / 6,000 = 29.5", say 30".
height of footing required = 2.2 x c x √(Pu/Af) + 4" ≥ 10"
h = 3.71" + 4" = 7.71" so use 10"
Reinforcement = 0.0018 x b x h = 0.0018 x 30 x 10 = 0.54 sq in
Use (3) #4 bars, Asteel = 0.2 x 3 = 0.6 sq in ≥ 0.54 sq in
Development Length ld = 22" (ACI 318-05 (12.2) for embedment into foundation wall.
Side and bottom cover = 3" (7.7.1)
Foundation Walls (14.3)
Vertical reinforcement area = 0.0012 x 12" x 12" = 0.1728 Sq in/ft (14.3.2)
Maximum spacing = 18" (14.3.5)
Vertical reinforcement @ 18" = 0.1728 x 1.5' = 0.259 sq in/ft
Two #4 bars @ 18" spacing = 0.4 sq in ≥ 0.259
Horizontal Reinforcement (14.3.3)
Asteel = 0.002 x 12" x 48" = 1.152 sq in, use 6 #4 bars = 1.2 sq in
For 64" high wall, Asteel = 0.002 x 12" x 64" = 1.536 sq in, use 8 #4 bars =1.6 sq in
Footings 10" thick
Footing concrete volume = (55.5 x 2.5 x 0.84 x 3) + (55.5 x 2 x 0.84) + ((12.5 + 14.5 + 8.25) x 2.5 x 2 x 0.84) = 591 cubic feet concrete, equivalent to 21.9 cubic yards
200' outside perimeter
Forming required = 200.5' + 126' + 130' + 117.5' = 574'
All rebars 1/2" DIA
Vent drains through footing
10" high form boards
55' 6" x 2
50' 6" x 6
12' 6" x 2
14' 6" x 2
8' 3" x 2
485' of 10" wide footing form boards
3/8" x 1-1/2" threaded inserts on 24" centers for foundation wall forming 292 total
Securing piping and sleeves inside footing forms. Wrap pipes with cardboard where embedded in footing for movement sleeve.
Footing perimeter = 292'
#4 rebars 20' lengths = 97
#4 rebars transverse 24" long = 206
Rebar length horizontally in footing = 936 feet
3" rebar support chairs = 73
Wire tieing = 1,304
Number of cuts = 650
Number of bends = 444
Estimated labor hours =
Splicing
Use all "Class B" splices (most conservative)
Class B lap length = 1.3 x tension development length
#4 bars = 1.3 x 19.0 = 25" for 4,000 psi concrete
#5 bars = 1.3 x 23.7 = 31"