Tomlinson
This widely used method adopts undrained shear strength parameters to calculate the pile bearing capacity. It further assumes that the pile shaft resistance depends on the pressure due to overburden surcharge.
The pile shaft resistance is given by:
where: | ca, j | - | adhesion in the jth layer (shear stress between the pile skin and the surrounding soil) |
As, j | - | area of the pile shaft in the jth layer | |
αj | - | empirical adhesion coefficient (depends on the type of soil, type of pile, etc.) in the jth layer | |
cu, j | - | undrained cohesion in the j-th layer (undrained shear strength) |
The empirical adhesion coefficient α is back-calculated by the program. Its values, however, can be manually adjusted in the "Add new soil" dialog window.
The pile base resistance is given by:
where: | qb | - | unit pile base resistance |
Ab | - | pile base area | |
cu | - | undrained shear strength |