## Infinite Slope v. 1.02 Edu.

Software features and limitations.

Scheme of the slope in the program's graphical interface.

**Features**

The position of free phreatic surface has a determinant role on stability conditions, therefore it is very important to be able to control its depth

*z*

*w*.

The polygon of forces for the slice is useful to control how the equilibrium evolves when changing a parameter.

While user can evaluate the factor of safety

*F(z)*for a generic slip surface (at depth

*z*) often its necessary to compare the obtained value to the minimum value of

*F*(at depth

*z*

*crit*) called the

*Factor of safety*of the slope.

All main variables can be controlled in interactive mode in order to understand their influence with an immediate visual perception.

The presence of the bedrock at depth

*z*

*bed*helps to give a lower limit to depths for the position of the failure surface, which makes the research of a critical depth

*zcrit*more realistic.

All features included in version v. 1.02 Edu are listed below:

- Input of weights either via porosity
*n*and unit weight od solids*γs*or directly through*γsat*,*γ*and*γd*. - Variable position of free phreatic surface at depth
*zw*. - Factor of Safety
*F(z)*for a generic slip surface (at depth*z*). - Factor of Safety
*F*of the slope, wich represent the minimum value corresponding to the critical slip surface (at depth*zcrit*). - Back analysis of a failure condition to determine
*φ'*or*c'*. - Position of the bedrock at depth
*zbed*which represent a layer of infinite strength. - Updated scheme of slope geometry with clear indications.
- Polygon of forces for the equilibrium of the slice.
- Suggestions and warnings about input data and on the results.
- Assessment of slope stability.
- Variable allowable value of the Factor of Safety.
- Unit weight of the soil above groundwater free surface can be input separately.
- Forces, stresses and pore pressures calculated for the single slice of unitary width.

**Limitations**

The model is suitable to analyse stability conditions of slopes with direction of stratification parallel to the slope. In many cases of mudflows and in any case where the failure surface is expected or found planar and parallel to the slope. For slopes made of fine grained soils in deep homogeneous layers the used model is often not suitable to represent a correct interpretation of

failure mechanisms (circular or not planar) and isn't able to give a reasonable factor of safety for the slope.

- The version does not consider seismic forces.
- No interventions on the slope is considered.
- No open/save options are implemented.
- Theory on non-saturated soils is neglected.