AS 4678
AS 4678-2002 — Earthquake, I20.1 (Amdt 2, 2008)
AS 4678-2002 (Amdt 2, 2008)Revision 2Required 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 · Slope convention · Not yet validated
The normative I20.1 is followed over the informative J2(c)/(f), which give 1.25 / 0.8 (owner decision); Table J1 is captioned 'not including wind and earthquake loads'.
Known limitations
- Live load carried directly by the structure takes 0.5 (I20.1): use a custom copy.
- The earthquake category C_er static check (Table I4: dead load ×1.5) is not provided.
- kh and kv are entered in the analysis options (I13, I14: kh = 0.5a or amplified; kv is often 0).
- The structure classification factor Φn (Table 5.2) multiplies reinforcement only, as eqs 5.5 and B4 do; Cl 5.1 can be read to apply it to soil strata too, which Slope does not.
- Layer rupture needs the product of the Appendix K reduction factors on each element, entered as its reciprocal: 1 / (Φup·Φrc·Φue·Φri·Φrt·Φrs·Φrst·Φud).
- Anchors and nails use Appendix B (informative) with the permanent Φk = 0.8; a temporary anchor (Φk 0.85 or 0.9) needs a custom copy.
- Anchor and nail pull-out is a characteristic bond stress × Φk·Φb·Φn (B4.2.3, B4.3). A bulb anchor designed by eq B4(2) or an under-reamed anchor by eq B4(3) has no Φk: use a custom copy with pull-out ×0.7 and a stated bond whose resistance per metre is N1·tan φ* (B4(2)) or D·c* (B4(3)), and for B4(3), which has no Φn, structure class B.
- A layer's pull-out factor is the one of the soil at the middle of each bonded length (beyond and inside the slip surface); a length spanning two soil conditions takes one factor, not a length-weighted one.
- Direct sliding across a layer takes a′·tanφ′ and a′bc·c′ of the characteristic soil × Φu × Φn (eq 5.5(2)); Table 5.4 gives Φu for controlled fill only, so a layer in other soil is not checked.
- Piles are designed to AS 2159 (Cl 5.3) and are unfactored here; other strength models (Hoek–Brown, hyperbolic) are unfactored.
- AS 4678 excludes walls over 15 m, soft ground and land slips (Cl 1.2.1) and revetment-type slopes (Appendix E, E1).
Values
Actions
| Soil weightγ | Unfavorable | ×1.00 |
| Favorable | ×1.00 | |
| Permanent loadγG | Unfavorable | ×1.00 |
| Favorable | ×1.00 | |
| Variable loadγQ | Unfavorable | ×0.40 |
| Favorable | ×0.00 | |
| Seismic coefficientγE | ×1.00 | |
Resistance
| Earth / global resistanceγRe | ×1.00 | |
Materials
| Effective cohesionγc′ | Controlled fill (class I) | ×0.90 |
| Controlled fill (class II) | ×0.75 | |
| Uncontrolled fill | ×0.50 | |
| In situ | ×0.70 | |
| Friction (tanφ′)γφ | Controlled fill (class I) | ×0.95 |
| Controlled fill (class II) | ×0.90 | |
| Uncontrolled fill | ×0.75 | |
| In situ | ×0.85 | |
| Undrained strength (cu)γcu | Controlled fill (class I) | ×0.60 |
| Controlled fill (class II) | ×0.50 | |
| Uncontrolled fill | ×0.30 | |
| In situ | ×0.50 | |
| Shear strength (other models)— | ×1.00 | |
Reinforcement
| Anchor — tendonγt | ×0.72 | |
| Anchor — pull-outγpo | ×0.56 | |
| Nail — barγt | ×0.72 | |
| Nail — pull-outγpo | ×0.56 | |
| Geosynthetic — ruptureγt | ×1.00 | |
| Geosynthetic — pull-outγpo | Controlled fill (class I) | ×0.80 |
| Controlled fill (class II) | ×0.80 | |
| Uncontrolled fill | ×0.75 | |
| In situ | ×0.75 | |
| Geosynthetic — sliding acrossfs | Controlled fill (class I) | ×0.80 |
| Controlled fill (class II) | ×0.80 | |
| Steel strip — ruptureγt | ×1.00 | |
| Steel strip — pull-outγpo | Controlled fill (class I) | ×0.80 |
| Controlled fill (class II) | ×0.80 | |
| Uncontrolled fill | ×0.75 | |
| In situ | ×0.75 | |
| Steel strip — sliding acrossfs | Controlled fill (class I) | ×0.80 |
| Controlled fill (class II) | ×0.80 | |
| Steel grid — ruptureγt | ×1.00 | |
| Steel grid — pull-outγpo | Controlled fill (class I) | ×0.80 |
| Controlled fill (class II) | ×0.80 | |
| Uncontrolled fill | ×0.75 | |
| In situ | ×0.75 | |
| Steel grid — sliding acrossfs | Controlled fill (class I) | ×0.80 |
| Controlled fill (class II) | ×0.80 | |
Sources
Document: AS 4678-2002 (Amdt 2, 2008)
Actions
| Factor | Value | Source |
|---|---|---|
| Soil weight — unfavorable | ×1.00 | I20.1, Table J1 load case C: γg = 1.0, PDF p103, p106 · Not yet validated |
| Soil weight — favorable | ×1.00 | I20.1, Table J1 load case C: γg = 1.0, PDF p103, p106 · Not yet validated |
| Permanent load — unfavorable | ×1.00 | I20.1, Table J1 load case C: γg = 1.0, PDF p103, p106 · Not yet validated |
| Permanent load — favorable | ×1.00 | I20.1, Table J1 load case C: γg = 1.0, PDF p103, p106 · Not yet validated |
| Variable load — unfavorable | ×0.40 | I20.1, Table J1 load case C, long-term (Note 2), PDF p103, p106 · Not yet validated |
| Variable load — favorable | ×0.00 | 4.1(a)(iv), PDF p33 · Slope convention · Not yet validated — The lower factor is used where it is more critical (4.1(a)(iv)); a helping variable load is left out. |
| Seismic coefficient | ×1.00 | J2, J2(c), (f): 1.0 Feq, PDF p105 · Not yet validated |
Materials
| Factor | Value | Source |
|---|---|---|
| Effective cohesion, controlled fill (class I) | ×0.90 | 5.2.1, Table 5.1(A), controlled fill Class I, Φuc, PDF p36 · Not yet validated |
| Effective cohesion, controlled fill (class II) | ×0.75 | 5.2.1, Table 5.1(A), controlled fill Class II, Φuc, PDF p36 · Not yet validated |
| Effective cohesion, uncontrolled fill | ×0.50 | 5.2.1, Table 5.1(A), uncontrolled fill, Φuc, PDF p36 · Not yet validated |
| Effective cohesion, in situ | ×0.70 | 5.2.1, Table 5.1(A), in situ material, Φuc, PDF p36 · Not yet validated |
| Friction (tanφ′), controlled fill (class I) | ×0.95 | 5.2.2, Table 5.1(A), controlled fill Class I, Φuφ, PDF p36 · Not yet validated |
| Friction (tanφ′), controlled fill (class II) | ×0.90 | 5.2.2, Table 5.1(A), controlled fill Class II, Φuφ, PDF p36 · Not yet validated |
| Friction (tanφ′), uncontrolled fill | ×0.75 | 5.2.2, Table 5.1(A), uncontrolled fill, Φuφ, PDF p36 · Not yet validated |
| Friction (tanφ′), in situ | ×0.85 | 5.2.2, Table 5.1(A), in situ material, Φuφ, PDF p36 · Not yet validated |
| Undrained strength (cu), controlled fill (class I) | ×0.60 | 5.2, Table 5.1(B), controlled fill Class I, Φuc, PDF p36 · Not yet validated |
| Undrained strength (cu), controlled fill (class II) | ×0.50 | 5.2, Table 5.1(B), controlled fill Class II, Φuc, PDF p36 · Not yet validated |
| Undrained strength (cu), uncontrolled fill | ×0.30 | 5.2, Table 5.1(B), uncontrolled fill, Φuc, PDF p36 · Not yet validated |
| Undrained strength (cu), in situ | ×0.50 | 5.2, Table 5.1(B), in situ material, Φuc, PDF p36 · Not yet validated |
| Shear strength (other models) | ×1.00 | 5.2, Table 5.1, PDF p36 · Slope convention · Not yet validated — AS 4678 gives strength factors for c′, φ′ and cu only; other strength models are unfactored. |
Resistance
| Factor | Value | Source |
|---|---|---|
| Earth / global resistance | ×1.00 | I20.1, Table J1 load case C, PDF p103, p106 · Slope convention · Not yet validated — The normative I20.1 is followed over the informative J2(c)/(f), which give 1.25 / 0.8 (owner decision); Table J1 is captioned 'not including wind and earthquake loads'. |
Reinforcement
| Factor | Value | Source |
|---|---|---|
| Anchor — tendon | ×0.72 | B4, eq B4(1): Φk 0.8 (Table B1) × Φt 0.9 (Table B2), PDF p51–53 · Slope convention · Not yet validated — Appendix B is informative; the permanent Φk = 0.8 (Table B1) is used. |
| Anchor — pull-out | ×0.56 | B4.2.3, B4.2.3 and B4.3: Φk 0.8 (Table B1) × Φb 0.7 (Table B2), PDF p51–53 · Slope convention · Not yet validated — B4.3 determines soil-anchor and soil-nail resistance 'generally as for rock anchors': B4.2.3's design bond stress, the ground's shear strength × the factors of Tables B1 and B2. Slope's bond (stated, or calculated from interface parameters) is that characteristic bond stress. Φn is applied to it as eq 5.5(2) does for layers; B4.2.3 does not name Φn. The empirical eqs B4(2) and B4(3) (bulb and under-reamed anchors) are not modelled. Appendix B is informative; the permanent Φk = 0.8 (Table B1) is used. |
| Nail — bar | ×0.72 | B4, eq B4(1): Φk 0.8 (Table B1) × Φt 0.9 (Table B2), PDF p51–53 · Slope convention · Not yet validated — Appendix B is informative; the permanent Φk = 0.8 (Table B1) is used. |
| Nail — pull-out | ×0.56 | B4.2.3, B4.2.3 and B4.3: Φk 0.8 (Table B1) × Φb 0.7 (Table B2), PDF p51–53 · Slope convention · Not yet validated — B4.3 determines soil-anchor and soil-nail resistance 'generally as for rock anchors': B4.2.3's design bond stress, the ground's shear strength × the factors of Tables B1 and B2. Slope's bond (stated, or calculated from interface parameters) is that characteristic bond stress. Φn is applied to it as eq 5.5(2) does for layers; B4.2.3 does not name Φn. The empirical eqs B4(2) and B4(3) (bulb and under-reamed anchors) are not modelled. Appendix B is informative; the permanent Φk = 0.8 (Table B1) is used. |
| Geosynthetic — rupture | ×1.00 | 5.5.1.6, eq 5.5(1), PDF p39 · Slope convention · Not yet validated — Td* = Tu·Φup·Φrc·Φue·Φri·Φrt·Φrs·Φrst·Φud·Φn: the reduction factors depend on the product and its design life (Appendix K), so their product is entered on each element, as its reciprocal (Slope's product factor divides). |
| Geosynthetic — pull-out, controlled fill (class I) | ×0.80 | 5.5.2, Table 5.4, pull-out, controlled fill, PDF p39 · Not yet validated |
| Geosynthetic — pull-out, controlled fill (class II) | ×0.80 | 5.5.2, Table 5.4, pull-out, controlled fill, PDF p39 · Not yet validated |
| Geosynthetic — pull-out, uncontrolled fill | ×0.75 | 5.5.2, Table 5.4, pull-out, natural or in situ soil, PDF p39 · Slope convention · Not yet validated — Table 5.4 names controlled fill and natural or in-situ soil only; uncontrolled fill is not controlled, so it takes the in-situ value. |
| Geosynthetic — pull-out, in situ | ×0.75 | 5.5.2, Table 5.4, pull-out, natural or in situ soil, PDF p39 · Not yet validated |
| Geosynthetic — sliding across, controlled fill (class I) | ×0.80 | 5.5.2, Table 5.4, sliding resistance across reinforcement surface, PDF p39 · Not yet validated |
| Geosynthetic — sliding across, controlled fill (class II) | ×0.80 | 5.5.2, Table 5.4, sliding resistance across reinforcement surface, PDF p39 · Not yet validated |
| Steel strip — rupture | ×1.00 | 5.5.1.6, eq 5.5(1), PDF p39 · Slope convention · Not yet validated — Td* = Tu·Φup·Φrc·Φue·Φri·Φrt·Φrs·Φrst·Φud·Φn: the reduction factors depend on the product and its design life (Appendix K), so their product is entered on each element, as its reciprocal (Slope's product factor divides). |
| Steel strip — pull-out, controlled fill (class I) | ×0.80 | 5.5.2, Table 5.4, pull-out, controlled fill, PDF p39 · Not yet validated |
| Steel strip — pull-out, controlled fill (class II) | ×0.80 | 5.5.2, Table 5.4, pull-out, controlled fill, PDF p39 · Not yet validated |
| Steel strip — pull-out, uncontrolled fill | ×0.75 | 5.5.2, Table 5.4, pull-out, natural or in situ soil, PDF p39 · Slope convention · Not yet validated — Table 5.4 names controlled fill and natural or in-situ soil only; uncontrolled fill is not controlled, so it takes the in-situ value. |
| Steel strip — pull-out, in situ | ×0.75 | 5.5.2, Table 5.4, pull-out, natural or in situ soil, PDF p39 · Not yet validated |
| Steel strip — sliding across, controlled fill (class I) | ×0.80 | 5.5.2, Table 5.4, sliding resistance across reinforcement surface, PDF p39 · Not yet validated |
| Steel strip — sliding across, controlled fill (class II) | ×0.80 | 5.5.2, Table 5.4, sliding resistance across reinforcement surface, PDF p39 · Not yet validated |
| Steel grid — rupture | ×1.00 | 5.5.1.6, eq 5.5(1), PDF p39 · Slope convention · Not yet validated — Td* = Tu·Φup·Φrc·Φue·Φri·Φrt·Φrs·Φrst·Φud·Φn: the reduction factors depend on the product and its design life (Appendix K), so their product is entered on each element, as its reciprocal (Slope's product factor divides). |
| Steel grid — pull-out, controlled fill (class I) | ×0.80 | 5.5.2, Table 5.4, pull-out, controlled fill, PDF p39 · Not yet validated |
| Steel grid — pull-out, controlled fill (class II) | ×0.80 | 5.5.2, Table 5.4, pull-out, controlled fill, PDF p39 · Not yet validated |
| Steel grid — pull-out, uncontrolled fill | ×0.75 | 5.5.2, Table 5.4, pull-out, natural or in situ soil, PDF p39 · Slope convention · Not yet validated — Table 5.4 names controlled fill and natural or in-situ soil only; uncontrolled fill is not controlled, so it takes the in-situ value. |
| Steel grid — pull-out, in situ | ×0.75 | 5.5.2, Table 5.4, pull-out, natural or in situ soil, PDF p39 · Not yet validated |
| Steel grid — sliding across, controlled fill (class I) | ×0.80 | 5.5.2, Table 5.4, sliding resistance across reinforcement surface, PDF p39 · Not yet validated |
| Steel grid — sliding across, controlled fill (class II) | ×0.80 | 5.5.2, Table 5.4, sliding resistance across reinforcement surface, PDF p39 · Not yet validated |