Description
- This package inherits all features in the [ Single-Floor (Basic) Package ] in addition to advanced modelling features of soil and piles. Therefore, it is used in advanced foundation (rafts and piled rafts) analysis and modelling.
-
In this package:
- Soil can be modelled as Winkler continuous area springs or as elastic half space (Soil-soil interaction) for raft foundation analysis.
- The pile-pile or the pile-soil-pile interactions can be also taken into consideration in modeling piled rafts.
- As a BIM centered package, the model can be exported from Autodesk Revit.
-
As a boundary element-based package:
- No internal discretization is required; which allowing analysis of huge applications.
- Micro piles modelling is allowed.
- The package supports real geometry modelling for foundation slab with different thicknesses, piles ( as real circular elements), beams, and loading areas (columns, walls, cores).
Features and Capabilities
Three different soil layering are allowed:
- Staviridis method, this method adopts a superposition scheme to calculate the equivalent soil stiffness.
- Bowles’ method, this method calculate the equivalent soil stiffness using the weighted average method.
- Equivalent spring method, this method is simply calculating the equivalent soil spring by modeling the layers as springs connected in series.
For piled-rafts:
- Pile-pile, pile-soil, soil-soil interaction effects are considered. The
P-PPAK is a tool to compute these interaction effects. - The soil-soil interaction effects are computed based on Mindlin’s, or Boussinesq's, or Steinbrenner’s.
- Pile-soil interaction effects are computed based on Mindlin’s solution.
-
Pile-pile interaction effects are considered via P-PPAK using three different ways:
- The elastic approach (based on Mindlin’s equation).
- The load transfer approach (based on Randolph empirical formulas).
- Field measurement input coefficients or extracted from any other 3D finite elements model.
- Also, friction and/or end bearing piles could be modelled.
O.E. Shehata, A.F. Farid, Y.F. Rashed. “Practical boundary element method for piled rafts”, Eng. Anal. Bound. Elem., 97 (2018), pp. 67 81, 10.1016/j.enganabound.2018.09.009
- Using the BEM together with the thick plate formulation, simple punching analysis can be considered for piled raft.
- Regions S1, S2,S3, and S4 show the shear stress distribution Qx as contour maps. It can be seen that, punching shear will be critical for external piles and internal loading zones (S3 and S4) in case of considering interactions effects. This is opposite to the case of ignoring interaction effects, which indicates that internal piles and external loading zones are the critical ones.
- This confirms the importance of considering interaction effects in design of practical examples.
O.E. Shehata, A.F. Farid, Y.F. Rashed. “Practical boundary element method for piled rafts”, Eng. Anal. Bound. Elem., 97 (2018), pp. 67 81, 10.1016/j.enganabound.2018.09.009
All features and capabilities of this package can be used to perform:
- Nonlinear analysis including all interaction effects for rafts or piled rafts via [ The Nonlinear Foundation Package ].
- Overall analysis of buildings including SSI via [ Overall Package ].
- Coupling with any other superstructure FEM analysis tool to analyze rafts/piled rafts on advanced foundation models [ SuperSubCoupling Tool ].
