Bearing Capacity of Pile in Rock
The pile base bearing capacity in rocks is calculated using the following formulas:
where: | qb | - | pile base resistance |
Ab | - | area of the pile base | |
σcd | - | ||
Ksp | - | loading factor | |
df | - | rock embedment length coefficient | |
Lr | - | length of the pile in rock | |
d | - | diameter of the pile base | |
s | - | distance of discontinuities | |
a | - | opening of discontinuities |
The input parameters for the calculation must meet the following conditions:
- Distance of discontinuities s min. 300 mm
- Opening of discontinuities a max. 5 mm (resp. 25 mm, if filled with soil or rock debris)
- Ratio of distance of discontinuities s to pile diameter d
- Ratio of opening of discontinuities a to distance of discontinuities s
The pile base resistance qb must be less than the design compressive strength of concrete fcd .
The resulting value of the bearing capacity of the foundation soil Rd is already reduced by the coefficient γR = 3.0, which is included in the Ksp coefficient. The program therefore does not react to the defined reduction coefficient of the vertical bearing capacity in the "Analysis settings".
The bearing capacity of the pile shaft in rocks is given by the formula:
where: | fs | - | skin friction |
As | - | area of the pile shaft in the rocks | |
σcd | - |