Code approach · partial factors¶
The user chooses the verification approach from a dropdown. Each approach defines the partial factors γ applied to actions and resistances, and the required FS.
Available approaches¶
| Code | Set | γG | γQ | γφ | γc | γR | Required FS |
|---|---|---|---|---|---|---|---|
| Characteristic (TA) | — | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | 1.30 (default, user-set) |
| NTC 2018 (A2+M2+R2) | A2+M2+R2 | 1.00 | 1.30 | 1.25 | 1.25 | 1.10 | 1.00 |
| EC7 — DA1 Comb. 1 | A1+M1+R1 | 1.35 | 1.50 | 1.00 | 1.00 | 1.00 | 1.00 |
| EC7 — DA1 Comb. 2 | A2+M2+R2 | 1.00 | 1.30 | 1.25 | 1.25 | 1.00 | 1.00 |
| EC7 — DA2 | A1+M1+R2 | 1.35 | 1.50 | 1.00 | 1.00 | 1.10 | 1.00 |
| EC7 — DA3 | A2+M2+R3 | 1.00 | 1.30 | 1.25 | 1.25 | 1.00 | 1.00 |
Applied factors¶
The "γ applied" chip strip immediately below the code selector shows the partial factors that are currently in use. Chips with γ = 1.00 are highlighted in green.
NTC 2018 §6.8 (Italian code)¶
The standard approach for natural slope stability under NTC 2018 is Approach 1 Combination 2 (A2+M2+R2):
- γG = 1.00, γQ = 1.30 — actions reduced (the weight is NOT amplified)
- γφ = γc = 1.25 — material reduced (friction and cohesion reduced)
- γR = 1.10 — resistance reduced (natural slopes); 1.20 for cut faces
Required FS in this set is 1.00 (since the partial factors are already applied; equivalent to ~1.30 in the characteristic equivalent).
When to use which¶
- Characteristic (TA): pre-design, comparison with literature, numerical verifications, didactic. NOT for executive design.
- NTC 2018 A2+M2+R2: standard for Italian projects.
- EC7 DA1 Comb. 1 / DA2: high γG = 1.35 — amplifies the weight as an unfavourable action. Conservative.
- EC7 DA1 Comb. 2 / DA3: parallel of NTC, reduces materials but not weight. More common in continental practice.
Required FS¶
For Allowable Stress (TA), the user can manually set the required FS (default 1.30 for slopes per NTC §6.8). For all NTC/EC7 approaches, the partial factors include the safety margin already, so FSreq = 1.00 (or 1.10 for NTC R2).
Verification result¶
The right panel shows:
compared with FSreq:
- ✓ green — verified (FS ≥ FSreq)
- ✗ red — not verified
The overturning verification Fr (moments around the toe) is shown below as a separate check.