Retaining walls (passive pressures)
Undrained analyses
Undrained passive smooth retaining wall (weightless soil)
| Benchmark | 2 |
| Result | 2 |
| Discrepancy on Collapse Load | 0% |
| Discrepancy on Input Parameters | 0% |
GENERAL DESCRIPTION: Simple retaining wall, horizontal soil surface.
ANALYSIS TYPE: Undrained, tension cutoff not modelled.
KEY DIMENSIONS: Wall height 1m.
ADEQUACY FACTOR LOADING: Passive horizontal load on wall (unit permanent load 1kN/m2).
BOUNDARY CONDITIONS: No surcharge; wall on smooth base; soil-wall interface smooth
SOIL PROPERTIES: c_u = 1 kN/m2, soil unit weight = 0 kN/m2.
PARTIAL FACTOR SET: Unity.
BENCHMARK SOLUTION: 2
REFERENCE: Powrie (2004) Soil Mechanics: Concepts and Applications. Taylor & Francis.
Undrained passive retaining wall, adhesion=0.5c_u (weightless soil)
| Benchmark | 2.39 |
| Result | 2.4 |
| Discrepancy on Collapse Load | 0.38% |
| Discrepancy on Input Parameters | 0.38% |
GENERAL DESCRIPTION: Simple retaining wall, horizontal soil surface.
ANALYSIS TYPE: Undrained, tension cutoff not modelled.
KEY DIMENSIONS: Wall height 1m.
ADEQUACY FACTOR LOADING: Passive horizontal load on wall (unit permanent load 1kN/m2).
BOUNDARY CONDITIONS: No surcharge; wall on smooth base; soil-wall interface adhesion = 0.5 c_u
SOIL PROPERTIES: c_u = 1 kN/m2, soil unit weight = 0 kN/m2.
PARTIAL FACTOR SET: Unity.
BENCHMARK SOLUTION: 2.390
REFERENCE: Powrie (2004) Soil Mechanics: Concepts and Applications. Taylor & Francis.
NOTES: Benchmark given is a lower bound.
Undrained passive retaining wall, full adhesion (weightless soil)
| Benchmark | 2.57 |
| Result | 2.6 |
| Discrepancy on Collapse Load | 0.93% |
| Discrepancy on Input Parameters | 0.93% |
GENERAL DESCRIPTION: Simple retaining wall, horizontal soil surface.
ANALYSIS TYPE: Undrained, tension cutoff not modelled.
KEY DIMENSIONS: Wall height 1m.
ADEQUACY FACTOR LOADING: Passive horizontal load on wall (unit permanent load 1kN/m2).
BOUNDARY CONDITIONS: No surcharge; wall on smooth base; full adhesion on soil-wall interface
SOIL PROPERTIES: c_u = 1 kN/m2, soil unit weight = 0 kN/m2.
PARTIAL FACTOR SET: Unity.
BENCHMARK SOLUTION: 2.571 ( (2+pi)/2)
REFERENCE: Powrie (2004) Soil Mechanics: Concepts and Applications. Taylor & Francis.
NOTES: Benchmark given is a lower bound.
Undrained passive smooth retaining wall
| Benchmark | 2.5 |
| Result | 2.5 |
| Discrepancy on Collapse Load | 0% |
| Discrepancy on Input Parameters | 0% |
GENERAL DESCRIPTION: Simple retaining wall, horizontal soil surface
ANALYSIS TYPE: Undrained, tension cutoff not modelled
KEY DIMENSIONS: Wall height 1m.
ADEQUACY FACTOR LOADING: Passive horizontal load on wall (unit load 1kN/m2)
BOUNDARY CONDITIONS: No surcharge; wall on smooth base; soil-wall interface smooth
SOIL PROPERTIES: c_u = 1 kN/m2, soil unit weight = 1 kN/m3
BENCHMARK SOLUTION: 2.5
REFERENCE: Powrie (2004) Soil Mechanics: Concepts and Applications. Taylor & Francis.
Undrained passive retaining wall, full adhesion
| Benchmark | 3.07 |
| Result | 3.1 |
| Discrepancy on Collapse Load | 0.78% |
| Discrepancy on Input Parameters | 0.78% |
GENERAL DESCRIPTION: Simple retaining wall, horizontal soil surface
ANALYSIS TYPE: Undrained, tension cutoff not modelled
KEY DIMENSIONS: Wall height 1m.
ADEQUACY FACTOR LOADING: Passive horizontal load on wall (unit load 1kN/m2)
BOUNDARY CONDITIONS: No surcharge; wall on smooth base; full adhesion on soil-wall interface
SOIL PROPERTIES: c_u = 1 kN/m2, soil unit weight = 1 kN/m3
BENCHMARK SOLUTION: 3.071 ( (3+pi)/2)
REFERENCE:
Linear variation of cohesion with depth
Undrained passive smooth retaining wall (weightless soil)
| Benchmark | 3 |
| Result | 3 |
| Discrepancy on Collapse Load | 0% |
| Discrepancy on Input Parameters | 0% |
GENERAL DESCRIPTION: Simple retaining wall, horizontal soil surface
ANALYSIS TYPE: Undrained, tension cutoff not modelled
KEY DIMENSIONS: Wall height 1m.
ADEQUACY FACTOR LOADING: Passive horizontal load on wall (unit load 1kN/m2)
BOUNDARY CONDITIONS: No surcharge; wall on smooth base; soil-wall interface smooth
SOIL PROPERTIES: c_u = 1 kN/m2 at soil surface, linear increase of strength with depth 1kN/m2/m, soil unit weight = 0 kN/m3
BENCHMARK SOLUTION: 3
REFERENCE:
Undrained passive smooth retaining wall
| Benchmark | 3.5 |
| Result | 3.5 |
| Discrepancy on Collapse Load | 0% |
| Discrepancy on Input Parameters | 0% |
GENERAL DESCRIPTION: Simple retaining wall, horizontal soil surface
ANALYSIS TYPE: Undrained, tension cutoff not modelled
KEY DIMENSIONS: Wall height 1m.
ADEQUACY FACTOR LOADING: Passive horizontal load on wall (unit load 1kN/m2)
BOUNDARY CONDITIONS: No surcharge; wall on smooth base; soil-wall interface smooth
SOIL PROPERTIES: c_u = 1 kN/m2 at soil surface, linear increase of strength with depth 1kN/m2/m, soil unit weight = 1 kN/m3
BENCHMARK SOLUTION: 3.5
REFERENCE:
Drained analyses
Drained passive smooth retaining wall (phi' = 30 degrees)
| Benchmark | 1.5 |
| Result | 1.5 |
| Discrepancy on Collapse Load | 0% |
| Discrepancy on Input Parameters | 0% |
GENERAL DESCRIPTION: Simple retaining wall, horizontal soil surface
ANALYSIS TYPE: Drained
WATER REGIME: Dry conditions
KEY DIMENSIONS: Wall height 1m.
ADEQUACY FACTOR LOADING: Passive horizontal load on wall (unit permanent load 1kN/m2).
BOUNDARY CONDITIONS: No surcharge; wall on smooth base; soil-wall interface smooth (delta = 0 degrees)
SOIL PROPERTIES: c'=0, phi = 30 degrees, soil dry unit weight = 1 kN/m3
PARTIAL FACTOR SET: Unity.
BENCHMARK SOLUTION: 1.500 (=3.0*1/2)
REFERENCE: Powrie (2004) Soil Mechanics: Concepts and Applications. Taylor & Francis.
Drained passive smooth retaining wall (phi' = 40 degrees)
| Benchmark | 2.3 |
| Result | 2.3 |
| Discrepancy on Collapse Load | 0.02% |
| Discrepancy on Input Parameters | 0% |
GENERAL DESCRIPTION: Simple retaining wall, horizontal soil surface
ANALYSIS TYPE: Drained
WATER REGIME: Dry conditions
KEY DIMENSIONS: Wall height 1m.
ADEQUACY FACTOR LOADING: Passive horizontal load on wall (unit load 1kN/m2)
BOUNDARY CONDITIONS: No surcharge; wall on smooth base; soil-wall interface smooth (delta = 0 degrees)
SOIL PROPERTIES: c'=0, phi = 40 degrees, soil dry unit weight = 1 kN/m3
BENCHMARK SOLUTION: 2.299 (=4.599*1/2)
REFERENCE: Powrie (2004) Soil Mechanics: Concepts and Applications. Taylor & Francis.
Drained passive smooth retaining wall (phi' = 50 degrees)
| Benchmark | 3.77 |
| Result | 3.77 |
| Discrepancy on Collapse Load | 0% |
| Discrepancy on Input Parameters | 0% |
GENERAL DESCRIPTION: Simple retaining wall, horizontal soil surface
ANALYSIS TYPE: Drained
WATER REGIME: Dry conditions
KEY DIMENSIONS: Wall height 1m.
ADEQUACY FACTOR LOADING: Passive horizontal load on wall (unit load 1kN/m2)
BOUNDARY CONDITIONS: No surcharge; wall on smooth base; soil-wall interface smooth (delta = 0 degrees)
SOIL PROPERTIES: c'=0, phi = 50 degrees, soil dry unit weight = 1 kN/m3
BENCHMARK SOLUTION: 3.7743 (=7.5486*1/2)
REFERENCE: Powrie (2004) Soil Mechanics: Concepts and Applications. Taylor & Francis.
Drained analyses with water pressures
Drained passive smooth retaining wall (phi' = 30 degrees)
| Benchmark | 29.43 |
| Result | 29.43 |
| Discrepancy on Collapse Load | 0% |
| Discrepancy on Input Parameters | 0% |
GENERAL DESCRIPTION: Simple retaining wall, horizontal soil surface
ANALYSIS TYPE: Drained
WATER REGIME: Dry conditions
KEY DIMENSIONS: Wall height 1m.
ADEQUACY FACTOR LOADING: Passive horizontal load on wall (unit load 1kN/m2)
BOUNDARY CONDITIONS: No surcharge; wall on smooth base; soil-wall interface smooth (delta = 0 degrees)
SOIL PROPERTIES: c'=0, phi = 30 degrees, soil dry unit weight = 19.62 kN/m3
BENCHMARK SOLUTION: 29.43 (=3*19.62/2)
REFERENCE: Powrie (2004) Soil Mechanics: Concepts and Applications. Taylor & Francis.
Drained passive smooth retaining wall (phi' = 30 degrees), wall submerged
| Benchmark | 14.72 |
| Result | 14.72 |
| Discrepancy on Collapse Load | 0% |
| Discrepancy on Input Parameters | 0% |
GENERAL DESCRIPTION: Simple retaining wall, horizontal soil surface, submerged
ANALYSIS TYPE: Drained
WATER REGIME: Water table above wall and soil
KEY DIMENSIONS: Wall height 1m.
ADEQUACY FACTOR LOADING: Passive horizontal load on wall (unit load 1kN/m2)
BOUNDARY CONDITIONS: No surcharge; wall on smooth base; soil-wall interface smooth (delta = 0 degrees)
SOIL PROPERTIES: c'=0, phi = 30 degrees, soil saturated unit weight = 19.62 kN/m3
BENCHMARK SOLUTION: 14.72 (=1.5*19.62*1/2). Effective weight of soil is half saturated weight.
REFERENCE: Follows from simple Rankine theory, Powrie (2004) Soil Mechanics: Concepts and Applications. Taylor & Francis.
Drained passive smooth retaining wall (phi' = 30 degrees), wall half submerged
| Benchmark | 25.75 |
| Result | 25.77 |
| Discrepancy on Collapse Load | 0.06% |
| Discrepancy on Input Parameters | 0% |
GENERAL DESCRIPTION: Simple retaining wall, horizontal soil surface, submerged
ANALYSIS TYPE: Drained
WATER REGIME: Water table 0.5m below soil surface acting on soil and both sides of wall
KEY DIMENSIONS: Wall height 1m.
ADEQUACY FACTOR LOADING: Passive horizontal load on wall (unit load 1kN/m2)
BOUNDARY CONDITIONS: No surcharge; wall on smooth base; soil-wall interface smooth (delta = 0 degrees)
SOIL PROPERTIES: c'=0, phi = 30 degrees, soil saturated unit weight = 19.62 kN/m3
BENCHMARK SOLUTION: 25.7513 (=1.5*19.62*7/8). Effective weight of soil is half saturated weight.
REFERENCE: Follows from simple Rankine theory, Powrie (2004) Soil Mechanics: Concepts and Applications. Taylor & Francis.