Pile Shaft Resistance
The bearing capacity of the pile shaft in cohesionless soils is given by the formula:
where: | K | - | coefficient of lateral earth pressure in the layer |
σef | - | effective stress at the middle of the layer | |
δ | - | pile skin friction angle (between pile material and surrounding soil) | |
fs,i | - | shaft resistance in the ith layer | |
α | - | adhesion between the pile and the surrounding soil | |
As,i | - | area of the pile shaft in the ith layer |
Coefficient of lateral earth pressure K is calculated by the program automatically, or it is also possible to input it manually in the "Adding new soils" dialog window.
The friction angle on the pile skin δ is taken according to the pile material:
- for concrete, wood: δ = φ
- for steel: δ = φ/2
Adhesion between the pile and the surrounding soil α is taken according to the pile technology:
- bored, CFA piles: α = cef
- driven piles: α=0
The friction angle δ and the adhesion α can also be entered manually.
For cohesive soils, the following formula applies:
where: | cu | - | total cohesion in the ith layer |
α | - |
Adhesion coefficient α is calculated by the program automatically, or it is also possible to input it manually in the "Adding new soils" dialog window.