Description
The settlements of a rigid square foundation on a lacustrine clay [1] are calculated with RFEM. One quarter of the foundation is modelled. The foundation has a width of 75.000 m in both sides. Construction stages are used to generate the results.
| Material | Lacustrine Clay | Modulus of Elasticity | E | 10.000 | MN/m2 |
| Shear Modulus | G | 3.846 | MN/m2 | ||
| Poisson's Ratio | ν | 0.300 | - | ||
| Specific Weight | γ | 17.000 | kN/m3 | ||
| Specific Weight | γsat | 18.000 | kN/m3 | ||
| Foundation | Modulus of Elasticity | E | 30000.000 | MN/m2 | |
| Poisson's Ratio | ν | 0.150 | - | ||
| Specific Weight | γsat | 50.000 | kN/m3 | ||
| Geometry | Foundation Length | l | 18.000 | m | |
| Foundation Width | b | 18.000 | m | ||
| Foundation Thickness | h | 2.000 | m | ||
| Load Cases | Foundation Self-weight | LC1 | - | - | |
| Soil Self-weight | LC2 | - | - | ||
RFEM Settings
- The borehole used for the generation of the soil massif has the lacustrine clay as an only soil layer and is 40.000 m long.
- The foundation is embedded in the soil massif by means of solid intersections.
- The length of the finite elements lFE for the soil is set to 4.000 m. A refinement of the mesh is considered around the foundation and lFE is set to 0.500 m.
- For the calculation phases, two static analysis settings are used:
| Static analysis settings | Analysis type | Options |
| SA1 | Geometrically linear | Non-symmetric direct solver if demanded by nonlinear model |
| SA2 | Geometrically linear | Non-symmetric direct solver if demanded by nonlinear model |
| Equilibrium for undeformed structure |
- The calculation phases are then defined using construction stages:
| Construction stage | Static analysis settings | Assigned load cases |
| CS1 | SA1 | LC2 |
| CS2 | SA2 | LC2 |
| CS3 | SA1 | LC2 and LC1 |
502x
28x
Results
The obtained displacements in x, y and z directions are compared to the results calculated with the software PLAXIS 3D:
| RFEM 6 | PLAXIS 3D | Ratio | |
| max ux [mm] | 14.4 | 14.5 | 0.99 |
| RFEM 6 | PLAXIS 3D | Ratio | |
| max uy [mm] | 13.0 | 13.7 | 0.95 |
| RFEM 6 | PLAXIS 3D | Ratio | |
| max uz [mm] | 110.4 | 111.0 | 0.99 |
