Bearing Capacity
The maximum bearing capacity of a single pile based on the values of tip resistance qc of the ith cone penetration test is given by:
where: | Fmax, i | - | maximum bearing capacity of the pile from ith CPT |
Fmax,base,i | - | maximum base resistance from ith CPT | |
Fmax,shaft,i | - | maximum shaft resistance from ith CPT |
If performing the analysis according to the factor of safety or the limit states theory, the bearing capacity of a single pile is obtained as an arithmetic average of n calculated bearing capacities:
If performing the analysis according to EN 1997-2, or NBN EN1997-1 ANB, final bearing capacity depends on correlation coefficients ξ3 and ξ4.
If performing the analysis according to the NEN 6743 standard then the approach for more CPTs is different and follows directly the NEN 6743 standard (article 5.3.2.2).
The maximum pile base resistance Fmax,base is provided by:
where: | Abase | - | pile base cross-sectional area |
pmax, base | - | maximum pressure at pile base from CPT results |
The maximum shaft resistance Fmax,shaft is provided by:
where: | Op | - | pile periphery in bearing soil |
pmax, shaft | - | maximum force on shaft (friction) from CPT results | |
ΔL | - | pile length, either length of activated shaft friction or length of expanded base | |
z | - | vertical dimension along pile axis |
The actual calculation of the maximum pressure at pile base pmax,base and the maximum force developed along the shaft pmax,shaft (determined according to the selected type of analysis selected in the "Pile CPT" tab).