GGU-STABILITY: Verification of sliding safety

Sliding safety verification is performed with the assistance of equivalent systems. Weight calculation is according to the information in the figure below.

The weight of the hatched area is determined. The lower right point of the body is taken as the x value of the lower end of the nail, and the y value as the lower edge of the concrete shell or exterior skin. The rear face is taken as a line running to the end of the uppermost nail (independent of the length of any other nails between these two points). The inclination of the rear wall face cannot be steeper than the inclination of the active earth pressure wedge (see further down).

The horizontal loading is taken from the active earth pressure. The vertical section for which the earth pressure is to be determined, is shown in the figure below.

As the GGU-STABILITY program also allows input of inclined layers, as well as many other features (e.g. consolidation, artesian water, etc.), which do not allow a classical earth pressure calculation via kah values, the earth pressure calculation will be carried out using a variation of the earth pressure wedge.

In order to take into consideration any inclination of the rear face of the wall, a reduction is carried out via the earth pressure coefficients kah for both a vertical rear face ( = 0) and an inclined rear face ( ≠ 0), after determining the earth pressure:

Sliding safety _G is calculated thus:

G_k = characteristic weight
H_d = design value of horizontal force

The friction angle is obtained from the mean of the soils in the base of the wall footing.