Interface¶
SPX is organised in eight tabs, in project order. Each one depends on the previous ones: there is no point jumping to design without the borehole entered.
| # | Tab | Delivers |
|---|---|---|
| 1 | Pile Cap Setup | Geometry, piles, materials |
| 2 | Borehole / NSPT | Subsoil profile |
| 3 | Soil Properties | Unit weights and parameters |
| 4 | Geotechnical Results | Bearing capacity and settlement |
| 5 | Structural Analysis | Internal forces along the pile |
| 6 | Design | Reinforcement |
| 7 | Detailing (DXF) | Construction drawing |
| 8 | Report | Calculation report |
Order matters¶
Step 6 feeds both final outputs: the drawing and the calculation report.
Changing earlier data invalidates what came after
Changing the diameter in tab 1, or an \(N_{SPT}\) in tab 2, invalidates capacity, settlement, internal forces and reinforcement. The program warns you when it detects a change in geotechnical parameters after a calculation, but the golden rule is to reprocess from tab 4 onwards whenever you go back.
General features¶
Dark mode¶
SPX has a light and a dark theme. The choice applies to the whole interface, including the generated charts — they are redrawn with the theme palette, not just inverted.
3D view¶
Two three-dimensional features help you check the input:
- Pile coordinate system — shows the X, Y and Z axes with the pile drawn, to settle any doubt about the direction of a force.
- 3D view of the pile cap — shows the piles in position, with the rakes applied. It is the quickest way to spot a swapped azimuth.
Processing¶
Long calculations — the finite element analysis and the geotechnical processing of many piles — show a progress window. The time grows with the number of piles and with the depth of the borehole.
Conventions¶
Before your first project, it is worth reading Conventions and units. The two points that cause the most errors:
- The soil classification selects the parameters. Silty sand and sandy silt have similar names and reversed compositions: swapping them changes \(K\) from 0.80 to 0.55 MPa.
- Positive axial force is compression. With a negative value the program switches to a tension calculation, ignoring the toe.