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

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

Software Requirements Specification for Slope Stability analysis Program

Functional Requirements