Calculate aprox. Caisson dia. with added skin friction
Calculate aprox. Caisson dia. with added skin friction
(OP)
I'm trying to figure out a recommended caisson diameter and depth for a structural load of 400 kips. I attached a table with recommended lateral load design.
Below is what I came up with.
450 #/sf (12.57SF) = 5,655 #/FT
5,655 lb/ft (57 ft) = 322,327.41 lb
=322.33 kips
400kip - 322k
=78kip
qu = 12 ksf
p = 78
qu=p/a
a = p/qu = 3.14d2/4
d=2.88
Any ideas?
Below is what I came up with.
450 #/sf (12.57SF) = 5,655 #/FT
5,655 lb/ft (57 ft) = 322,327.41 lb
=322.33 kips
400kip - 322k
=78kip
qu = 12 ksf
p = 78
qu=p/a
a = p/qu = 3.14d2/4
d=2.88
Any ideas?





RE: Calculate aprox. Caisson dia. with added skin friction
Or are you going to the top of the dense till and neglecting the first 18'?
Either way. Your Pr=Prs+Prb where Prs is contribution from skin friction and Prb is the contribution from the base.
Prs = (pi)*d*s*l s is skin friction
Prb = (pi)*[(d^2)/4]*bearing pressure at tip
If you know your length you can solve the equation (it will be a second degree polynomial)
If you are attempting to optimize the design then you've got to modify both length and diameter to find the best solution.
RE: Calculate aprox. Caisson dia. with added skin friction
qu = 6 KSF
Skin friction = 450 #/ft
Laffective = 37-18 = 19ft (no skin friction above the bell).
P total = 400 kip
sk = 94 kip
P = 306 kip
D= square root(4p/piQU) = 8.05 ft (Bell)
qu = 6 ksf @ 45ft
RE: Calculate aprox. Caisson dia. with added skin friction
RE: Calculate aprox. Caisson dia. with added skin friction
RE: Calculate aprox. Caisson dia. with added skin friction
RE: Calculate aprox. Caisson dia. with added skin friction