Geotechnical Tools
A structured collection of calculation tools covering key areas of geotechnical engineering, from site characterisation to analytical methods.
Shear Strength Tools
Effective Friction Angle (φ′) from Standard Penetration Test Resistance (N₆₀)
Effective friction angle is estimated from corrected SPT resistance N₆₀ using the empirical correlation cited by Peck, Hanson, and Thornburn (1974).
Soil Layer Profile
Enter corrected SPT resistance by depth. Effective friction angle uses φ′ ≈ 27.1 + 0.3N₆₀ − 0.00054N₆₀² (Peck, Hanson, and Thornburn, 1974).
When samples are imported from Projects and Boreholes with the project tool lock enabled, sample depth is read-only here (edit under Account > Projects). If available, N₆₀ is auto-filled from Standard Penetration Test (SPT) Corrections for N₆₀ and (N₁)₆₀ results saved to the project. Manual override is always allowed.
Narrow screen: swipe the table horizontally to see all columns and inputs.
| Borehole ID | Sample Depth(m) | N₆₀ | φ′(deg) | Action |
|---|---|---|---|---|
30.62 | ||||
32.33 | ||||
Depth vs φ′
Save Profile Analysis
Save current profile inputs and plot images to the active project folder.
Cloud save is available from Bronze upward. Register for an account to use cloud save. You can still use tools with manual inputs.
Select a project/borehole from the top-right dropdown first.
Important disclaimer
These results are simplified and indicative only. Please review the site-wide Disclaimer before using this tool in any engineering workflow.