Eurocode 7
Eurocode 7 — Earthquake (EN 1998-5:2004)
EN 1998-5:2004Revision 1Required FoS ≥ 1Seismic design situation
Use it in Slope
In a design, choose it under Analyze → Design factor set, and the PDF report runs it too.
Checked against the standard · Not yet validated
Known limitations
- ψ2 is 0.3 for every variable load; EN 1990 gives ψ2 per load category (0.3 for imposed loads A/B, 0 for traffic, snow and wind).
- Reinforcement is unfactored (Slope convention, not validated): EN 1998-5:2004 gives no seismic reinforcement factors and EN 1997-1 Table A.19 covers persistent and transient situations only; the absence of a factor does not show the unfactored capacity is adequate.
- The cyclic undrained strength τcy,u (γτcy = 1.25) has no input.
- Pseudo-static analysis must not be used for soils that develop high pore pressures or lose stiffness under cyclic loading (4.1.3.3(8)P).
Values
Actions
| Soil weightγ | Unfavorable | ×1.00 |
| Favorable | ×1.00 | |
| Permanent loadγG | Unfavorable | ×1.00 |
| Favorable | ×1.00 | |
| Variable loadγQ | Unfavorable | ×0.30 |
| Favorable | ×0.00 | |
| Seismic coefficientγE | ×1.00 | |
Resistance
| Earth / global resistanceγRe | ÷1.00 | |
Materials
| Effective cohesionγc′ | ÷1.25 | |
| Friction (tanφ′)γφ | ÷1.25 | |
| Undrained strength (cu)γcu | ÷1.40 | |
| Shear strength (other models)— | ÷1.25 | |
Sources
Document: EN 1998-5:2004
Actions
| Factor | Value | Source |
|---|---|---|
| Soil weight — unfavorable | ×1.00 | 4.1.3.4(4)P, PDF p18 · Not yet validated |
| Soil weight — favorable | ×1.00 | 4.1.3.4(4)P, PDF p18 · Not yet validated |
| Permanent load — unfavorable | ×1.00 | 4.1.3.4(4)P, PDF p18 · Not yet validated |
| Permanent load — favorable | ×1.00 | 4.1.3.4(4)P, PDF p18 · Not yet validated |
| Variable load — unfavorable | ×0.30 | 2.1(2)P · Slope convention · Not yet validated — ψ2 = 0.3 for every variable load (EN 1990 imposed loads A/B); EN 1990 gives ψ2 per load category. |
| Variable load — favorable | ×0.00 | 2.1(2)P · Slope convention · Not yet validated — The seismic combination (EN 1990 6.4.3.4) takes accompanying variable actions only; a helping one is omitted. |
| Seismic coefficient | ×1.00 | 4.1.3.3(5)P, PDF p17 · Slope convention · Not yet validated — Slope applies kh and kv as entered: enter kh = 0.5·α·S (×ST where 4.1.3.2(2) requires it). |
Materials
| Factor | Value | Source |
|---|---|---|
| Effective cohesion | ÷1.25 | 3.1(3), PDF p15 · Slope convention · Not yet validated — 3.1(3) lists no γc′; 1.25 by analogy with EC7 M2. |
| Friction (tanφ′) | ÷1.25 | 3.1(3), PDF p15 · Not yet validated |
| Undrained strength (cu) | ÷1.40 | 3.1(3), PDF p15 · Not yet validated |
| Shear strength (other models) | ÷1.25 | 3.1(3), PDF p15 · Slope convention · Not yet validated — γqu = 1.4 applies to unconfined-strength models; other strength models take 1.25 as for EC7 M2. |
Resistance
| Factor | Value | Source |
|---|---|---|
| Earth / global resistance | ÷1.00 | 4.1.3.4(4)P, PDF p18 · Not yet validated |