Input Data
Geometry
| Parameter | Value | Unit / note |
|---|---|---|
| Stem height above lower GL, H | m | |
| Stem thickness, t | m | |
| Corbel overall width, B | m | |
| Base depth below lower GL, d | m | |
| Bottom sole thickness, d0 | m | |
| Stem offset from left edge, x | m | |
| Berm height at wall, hb | m | |
| Berm slope | H:1V |
Retained Side Soil + UDL
| Parameter | Value | Unit / note |
|---|---|---|
| Unit weight, γ | kN/m³ | |
| Friction angle, φ | degrees | |
| Cohesion, c' | kN/m²; 0 = cohesionless | |
| Surcharge, q | kN/m² | |
| UDL setback, a | m behind wall; 0 = full height, large = none |
Water Pressure
| Parameter | Value | Unit / note |
|---|---|---|
| Retained-side water height, hw | m above lower GL; 0 = dry/drained | |
| Water unit weight, γw | kN/m³ |
Tie / Top Prop
| Parameter | Value | Unit / note |
|---|---|---|
| Use tie / prop? | simple 2D per metre run check | |
| Tie height above lower GL, yt | m; clamped to wall height | |
| Tie spring stiffness, kt | kN/m wall per m movement | |
| Assumed mobilisation movement, ut | mm wall movement at tie level | |
| Tie force cap, Tmax | kN/m; 0 = no cap |
Mobilisation movement: the tie/prop force is calculated as T = kt × ut. Because kt is entered per metre movement, 5 mm is converted to 0.005 m. Example: 1000 kN/m wall per m movement × 0.005 m = 5 kN/m. Reduce kt to represent positions further from the stiff return/slab prop.
Berm Passive Side
| Parameter | Value | Unit / note |
|---|---|---|
| Berm unit weight, γb | kN/m³ | |
| Berm friction angle, φb | degrees | |
| Berm cohesion, c'b | kN/m²; 0 = cohesionless | |
| Wall friction, δ | berm/wall interface; default conservative |
Footing / Toe Passive
| Parameter | Value | Unit / note |
|---|---|---|
| Toe passive mode | auto = include only when hb = 0 | |
| Front soil unit weight, γtp | kN/m³ | |
| Front soil friction angle, φtp | degrees | |
| Mobilisation factor, ηtp | 0 to 1 applied to Rankine passive |
Toe passive uses the entered base embedment depth d as the passive depth on the front face of the footing. In auto mode it is only included when berm height hb = 0, to avoid double counting with berm passive.
Wall / Check Factors
| Parameter | Value | Unit / note |
|---|---|---|
| Masonry/concrete unit weight | kN/m³ | |
| Base friction, μ | coefficient | |
| Use base friction? | sliding only | |
| Target FOS sliding | - | |
| Target FOS overturning | - | |
| Allowable bearing pressure | kN/m²; simple service check |
UDL treatment is automatic from setback a: a = 0 gives full-height surcharge, intermediate a gives active-wedge cut-off, and large a beyond the active wedge gives no UDL effect. Berm resistance is calculated by a finite Coulomb trial-wedge search. The berm slope and toe length therefore affect the available passive resistance. Wall friction can be included as a sensitivity. Bearing/eccentricity, simple retained-side water pressure, optional footing/toe passive resistance and an optional tie/top-prop spring are included. The tie force is calculated from the selected stiffness and an assumed mobilisation movement, so it remains a simple 2D sensitivity check rather than a 3D wall/slab interaction model. The corbel is modelled as a 75 mm bottom sole plus a 1:1 flare.
Sketch is diagrammatic. Dimensions are taken from the input cells, not from the drawing.