Analysis of Foundations (Spread Footing, Piles)
Designing a structure according to EN 1997-1 essentially follows the analysis of limit states.
Load reduction (DA1, DA2, DA3):
Load of foundation is taken as a result of analysis of the upper structure.
- load cases are determined according to rules provided by EN 1990:2002
- combinations of load cases are calculated according to EN 1991
The results of calculated combinations then serve as an input to "Spread footing" and "Pile" programs.
Either design (bearing capacity analysis, dimensioning of foundation) or service (analysis of settlement) load is considered. In Design approach 1, the analysis is performed for both the input design load (combination 1) and input service load (combination 2).
Only the structure self-weigh or the weight of soil above footing is multiplied by the partial factors in the program. The specified design load must be determined in accord with the EN 1990 and EN 1991 standards - individual components of load must be multiplied by the corresponding partial factors - the program does not change the input load any further.
Reduction of material (DA1, DA3):
Parameters of soils are automatically reduced by the corresponding partial factors.
Reduction of load (DA2), for piles (DA1, DA2, DA3):
The program "Pile" assumes partial factors being dependent on the type of pile (bored, driven, CFA). The window allows to define all partial factors. The analysis then adopts partial factors depending on the type of pile selected in the frame "Geometry". Verification of the tensile pile always considers the pile self weight. For the compressive pile the pile self-weight can be neglected depending on the settings in the frame "Load". The actual verification analysis is performed according to the theory of limit states.
Vertical and horizontal bearing capacity of foundation is reduced in the "Spread Footing" program.