Functional Requirements
This section provides the functional requirements, the tasks and behaviours that the software is expected to complete.
Read-and-Store: Read the inputs, shown in the table Required Inputs, and store the data.
Verify-Input: Verify that the input data lie within the physical constraints.
Determine-Critical-Slip-Surface: Determine the critical slip surface for the input slope, corresponding to the minimum factor of safety, by using IM:fctSfty, IM:nrmShrFor, and IM:intsliceFs to calculate the factor of safety for a slip surface and using IM:crtSlpId to find the slip surface that minimizes it.
Verify-Output: Verify that the minimum factor of safety and critical slip surface satisfy the physical constraints shown in Properties of a Correct Solution.
Display-Input: Display as output the user-supplied inputs listed in Tab:inputsToOutputTable.
Display-Graph: Display the critical slip surface of the 2D slope, as determined from IM:crtSlpId, graphically.
Display-Factor-of-Safety: Display the value of the factor of safety for the critical slip surface, as determined from IM:fctSfty, IM:nrmShrFor, and IM:intsliceFs.
Display-Interslice-Normal-Forces: Using IM:fctSfty, IM:nrmShrFor, and IM:intsliceFs, calculate and graphically display the interslice normal forces.
Display-Interslice-Shear-Forces: Using IM:fctSfty, IM:nrmShrFor, and IM:intsliceFs, calculate and graphically display the interslice shear forces.
Write-Results-To-File: Provide the option of writing the output result data, as given in FR:Display-Input, FR:Display-Graph, FR:Display-Factor-of-Safety, FR:Display-Interslice-Normal-Forces, and FR:Display-Interslice-Shear-Forces, to a file.
| Symbol | Description | Units |
|---|---|---|
| \(\text{(x,y)}\) | Cartesian position coordinates | \({\text{m}}\) |
| \(c’\) | Effective cohesion | \({\text{Pa}}\) |
| \(\mathit{const_f}\) | Decision on f | – |
| \({{x_{\text{slip}}}^{\text{maxEtr}}}\) | Maximum entry \(x\)-coordinate | \({\text{m}}\) |
| \({{x_{\text{slip}}}^{\text{maxExt}}}\) | Maximum exit \(x\)-coordinate | \({\text{m}}\) |
| \({{x_{\text{slip}}}^{\text{minEtr}}}\) | Minimum entry \(x\)-coordinate | \({\text{m}}\) |
| \({{x_{\text{slip}}}^{\text{minExt}}}\) | Minimum exit \(x\)-coordinate | \({\text{m}}\) |
| \({\boldsymbol{x}_{\text{slope}}}\) | \(x\)-coordinates of the slope | \({\text{m}}\) |
| \({\boldsymbol{x}_{\text{wt}}}\) | \(x\)-coordinates of the water table | \({\text{m}}\) |
| \({{y_{\text{slip}}}^{\text{max}}}\) | Maximum \(y\)-coordinate | \({\text{m}}\) |
| \({{y_{\text{slip}}}^{\text{min}}}\) | Minimum \(y\)-coordinate | \({\text{m}}\) |
| \({\boldsymbol{y}_{\text{slope}}}\) | \(y\)-coordinates of the slope | \({\text{m}}\) |
| \({\boldsymbol{y}_{\text{wt}}}\) | \(y\)-coordinates of the water table | \({\text{m}}\) |
| \({γ_{\text{dry}}}\) | Soil dry unit weight | \(\frac{\text{N}}{\text{m}^{3}}\) |
| \({γ_{\text{sat}}}\) | Soil saturated unit weight | \(\frac{\text{N}}{\text{m}^{3}}\) |
| \({γ_{w}}\) | Unit weight of water | \(\frac{\text{N}}{\text{m}^{3}}\) |
| \(φ’\) | Effective angle of friction | \({{}^{\circ}}\) |
Required Inputs following FR:Read-and-Store
| Symbol | Name |
|---|---|
| \(\mathit{const_f}\) | decision on f |
| \({{x_{\text{slip}}}^{\text{maxExt}}}\) | maximum exit \(x\)-coordinate |
| \({{x_{\text{slip}}}^{\text{maxEtr}}}\) | maximum entry \(x\)-coordinate |
| \({{x_{\text{slip}}}^{\text{minExt}}}\) | minimum exit \(x\)-coordinate |
| \({{x_{\text{slip}}}^{\text{minEtr}}}\) | minimum entry \(x\)-coordinate |
| \({{y_{\text{slip}}}^{\text{max}}}\) | maximum \(y\)-coordinate |
| \({{y_{\text{slip}}}^{\text{min}}}\) | minimum \(y\)-coordinate |
Inputs to be Returned as Output following FR:Display-Input