Scope by code
What Rischio computes for footings under AASHTO LRFD, 10th edition, article by article: each check and method, computed, in part or not.
Each check and method the code asks of a footing, in the code’s order, and whether Rischio computes it. The list comes from the engine itself, so it changes with every release.
AASHTO LRFD, 10th edition
| Article | What the code asks | Rischio |
|---|---|---|
| 10.6.1.1 | Spread footings: isolated, strip and combined footings (mats as combined footings) | In part |
| 3.4.1, Table 3.4.1-1 | Strength I: basic vehicular use without wind | |
| 3.4.1, Table 3.4.1-1 | Strength II (permit vehicle), III (wind on structure), V (vehicle with wind) | |
| 3.4.1, Table 3.4.1-1 | Service I: all loads at 1.00 | |
| 3.4.1, Table 3.4.1-1 | Extreme Event I: γp 1.00, γEQ on LL project-specific, EQ 1.00 | |
| 3.4.1, Table 3.4.1-1 | Extreme Event II: ice, vessel or vehicle collision, check flood | |
| 3.11.5.4; C3.4.1 | Passive earth pressure: a resistance, no load factor (kp for Rep) | Not computed |
| 10.6.1 | General considerations | In part |
| 10.6.1.2 | Bearing depth: top of footing below the scour check flood's scour; base below frost | In part |
| 10.6.1.3 | Effective dimensions B′ = B − 2eB, L′ = L − 2eL, for bearing and settlement | Computed |
| 10.6.1.3; C10.6.1.3 | A footing that is not rectangular: similar procedures, by judgment | Computed |
| 10.6.1.4; 11.6.3.2 | Bearing stress on soil: uniform over the effective area | Computed |
| 10.6.1.4; 11.6.3.2 | Bearing stress on rock: linear (triangular or trapezoidal) | Not computed |
| 10.6.1.7 | Uplift: resistance to uplift and structural strength | Not computed |
| 10.6.1.8 | Nearby structures: effects both ways | Not computed |
| 10.5.2, 10.6.2 | Service limit state | |
| 10.5.2.1, 10.6.2.1 | Vertical movement: total and differential settlement | In part |
| 10.6.1.3 | Settlement on B′ × L′ with the load at its centroid | Computed |
| 10.6.2.4.1, Figure 10.6.2.4.1-1 | Stress below the footing: zone of influence; Boussinesq contours | Computed |
| 10.6.2.4.1, Eq. 10.6.2.4.1-1 | St = Se + Sc + Ss, each layer by its own procedure | Computed |
| 10.6.2.4.2c | Schmertmann method: Iz diagrams by L/B, C1, C2, E from N160 or qc times X | Computed |
| 10.6.2.4.2a | Elastic theory | Computed |
| 10.6.2.4.3, Eqs. 10.6.2.4.3-1 to -3 | Primary consolidation from void ratio: OC, NC, underconsolidated | In part |
| 10.6.2.4.3, Eqs. 10.6.2.4.3-4 to -6 | Primary consolidation from vertical strain (Crε, Ccε) | Not computed |
| 10.6.2.4.3, Eq. 10.6.2.4.3-7, Fig. -3 | Three-dimensional consolidation where B is small against Hc: μc (EPRI 1983) | Not computed |
| 10.6.2.4.3, Eq. 10.6.2.4.3-8, Fig. -4 | Time to a degree of consolidation, t = T Hd²/cv | Computed |
| 10.6.2.4.4 | Settlement on rock: < 0.5 in. on fair to very good rock; else ρ = qo(1 − ν²) r Ip / (144 Em) | Not computed |
| 10.5.2.2.1; 10.6.2.2 | Tolerable movement criteria: empirical procedures or structural analyses | Computed |
| 10.5.2.2.2; C10.6.2.4.2a | Differential movement between foundations; 0.5 in. minimum differential | Not computed |
| 10.5.2.1; 10.5.2.2.1 | Horizontal movement and rotation under all service combinations | Not computed |
| 10.5.2.1; 10.5.5.1 | Scour design flood: deflection criteria after scour, φ 1.0 | Not computed |
| 10.6.2.5.1; Table C10.6.2.5.1-1 | Presumptive bearing resistance, at the service limit state only | Not computed |
| 10.6.2.5.2 | Rock: by RMR, capped by qu and 0.3 f′c | Not computed |
| 10.5.2.3 | Abutment transitions: movements from the embankment behind | Not computed |
| 10.5.3.1, 10.5.3.2, 10.6.3 | Strength limit state | |
| 10.6.3.1.1, Eq. 10.6.3.1.1-1 | Bearing on soil: qR = φb qn ≥ factored pressure on B′L′, each combination | Computed |
| 10.6.3.1.2a, Eqs. 10.6.3.1.2a-1 to -4 | qn = c Ncm + γq Df Nqm Cwq + 0.5 γf B Nγm Cwγ | Computed |
| 10.6.3.1.2a | qn by accepted soil mechanics theories: Meyerhof's general bearing capacity equation, chosen | Computed |
| 10.6.3.1.2c, Tables 10.6.3.1.2c-1 and -2 | Footings on or near slopes: qn × RCBC (Leshchinsky and Xie), by the slope stability factor Ns | Not computed |
| 10.6.3.1.2e, Eqs. -1 to -3 | Undrained, stronger over softer: Nm = 1/βm + κ sc Nc ≤ sc Nc | Computed |
| 10.6.3.1.2e, Fig. 10.6.3.1.2e-2 | Undrained, softer over stiffer: Nm from EPRI's chart | Not computed |
| 10.6.3.1.2f, Eq. 10.6.3.1.2f-1 | Drained upper layer over a weaker one | Computed |
| 10.6.3.1.3 | Semi-empirical bearing from in-situ tests | Not computed |
| Eq. 10.6.3.1.3-1 | SPT in sand: qn = (N160 B/5)(Cwq Df/B + Cwγ), N160 over 1.5B | Not computed |
| Eq. 10.6.3.1.3-2 | CPT: qn = (qc B/40)(Cwq Df/B + Cwγ), qc over B | Not computed |
| 10.6.3.2.1 | Bearing on rock: discontinuities, weathering; RMR where competency is not evident | Not computed |
| 10.6.3.2.2 | Semi-empirical: correlation with the Geomechanics RMR | Not computed |
| 10.6.3.2.3 | Analytic: rock mass strength, failure through discontinuities | Not computed |
| 10.5.3.2; 10.6.3.3 | Eccentricity (overturning) with factored loads | Computed |
| 10.6.3.3 | On soil: e ≤ B/3 and L/3 | Computed |
| 10.6.3.3 | On rock: e ≤ 0.45B and 0.45L | Not computed |
| 10.6.3.4, Eq. 10.6.3.4-1 | Sliding: RR = φτ Rτ + φep Rep ≥ factored horizontal load | In part |
| Eq. 10.6.3.4-2 | Cohesionless: Rτ = C V tan φf, C 1.0 cast against soil, 0.8 precast | In part |
| 10.6.3.4, Fig. 10.6.3.4-1 | Clay on ≥ 6 in. of compacted granular material: lesser of su and half the normal stress | Computed |
| 10.6.3.4; C10.6.3.4 | Passive resistance Rep available through the design life; its future removal | Not computed |
| 10.5.3.1; 10.6.3.5; 10.5.5.2.1; 3.4.1 | Overall stability, Strength I with γEV 1.00 and φ of 11.6.3.7 | Not computed |
| 10.5.4.1; 10.6.4.1 | Extreme event limit state | |
| 10.6.4.1; 10.5.5.3.3 | Bearing resistance, Extreme Event I loads, φ 1.0 | In part |
| 10.6.4.2; 11.6.5.1 | Eccentricity: middle 2/3 at γEQ 0 to middle 8/10 at γEQ 1.0, linear; γEQ 0 if LL reduces e | In part |
| 10.6.4.1; 10.5.5.3.3 | Sliding, φ 1.0 | In part |
| 10.6.4.1; 3.4.1 | Overall stability, Extreme Event I | Not computed |
| 10.5.5.3.2 | Scour check flood: φ 1.0, with debris loads | In part |