Unit Pile Base Resistance
Unit pile base resistance for non-cohesive soils is given by:
where: | fb | - | |
σefb | - | effective stress on the pile base | |
Nq | - | bearing capacity factor | |
qb,max | - | maximum limit for unit pile base resistance | |
φ | - | angle of internal friction |
Unit resistance qb cannot be higher than the maximum limit of unit pile base resistance qb,max. This limit can be input manually or calculated in the "Vertical cap." frame.
According to CTE-DB SE-C the maximum limit for unit pile base resistance is 20000 kPa. If the soft soil layer with lower resistance is under the pile base, the qb,max is calculated according to the formula:
where: | D | - | pile diameter |
H | - | distance of soft soil layer from the pile base | |
cu | - | undrained shear strength of the soft soil |
Influence of soft soil layer