Find the caisson capacity per the following information. D=5’
ABP=12ksf L1=15’ L2=30’ ASF1=4 ksf ASF2=2 ksf
Using the formula:
Caisson Capacity = ABP x (L1 + 0.5D) + ASF1 x (L1 + L2 + D) + ASF2 x D
Plugging in the values:
Caisson Capacity = 12 ksf x (15 ft + 0.5 x 5 ft) + 4 ksf x (15 ft + 30 ft + 5 ft) + 2 ksf x 5 ft
Caisson Capacity = 180 kip + 540 kip + 10 kip
Caisson Capacity = 730 kip
Therefore, the caisson capacity is 730 kips (kilo-pounds).
To find the caisson capacity, we can use the following formula:
Caisson Capacity = Bottom Area x Ultimate Unit Skin Resistance
1. Calculate the bottom area of the caisson:
The bottom area is determined by the diameter (D) of the caisson. Since the diameter is given as 5', we need to convert it to feet. 1 foot is equal to 12 inches, so 5 feet is equal to 5 x 12 = 60 inches.
Using the formula for the area of a circle:
Bottom Area = π x (D/2)^2
Substituting the value of D:
Bottom Area = 3.1416 x (60/2)^2
Bottom Area = 3.1416 x 30^2
Bottom Area = 3.1416 x 900
Bottom Area ≈ 2827.43 square feet
2. Calculate the ultimate unit skin resistance:
The ultimate unit skin resistance depends on the soil properties and is given as the allowable soil friction (ASF) values. Two ASF values are provided: ASF1 = 4 ksf and ASF2 = 2 ksf.
For the purpose of this calculation, we will use the higher ASF value (ASF1) to determine the caisson capacity.
Ultimate Unit Skin Resistance = ASF1
Substituting the value of ASF1:
Ultimate Unit Skin Resistance = 4 ksf
3. Calculate the caisson capacity:
Caisson Capacity = Bottom Area x Ultimate Unit Skin Resistance
Substituting the values of Bottom Area and Ultimate Unit Skin Resistance:
Caisson Capacity ≈ 2827.43 square feet x 4 ksf
Caisson Capacity ≈ 11,309.72 kips
Therefore, the caisson capacity per the given information is approximately 11,309.72 kips.