GGU-UNDERPIN: Base inclination

Base inclination is generally carried out to increase the sliding safety to the required level.

The idealisation of the body without base inclination to an equivalent structural system (elastic curve) presents no problems, because the stiffness of the individual partial calculations can be calculated from the horizontal thickness. However, the wedge shaped extension that normally occurs with base inclination is contradictory to the demands which arise when the wall is analysed as an elastic curve.

In order to disqualify contradictory results from the outset, the base inclination is not taken into consideration when determining the action effects. Only when verifying the safety against sliding are the active and passive earth pressures at the left and right of the wedge cumulated and this component allocated to the horizontal force when verifying the safety against sliding. When verifying the bearing capacity safety, base inclination is taken into consideration. The additional horizontal force component is not incorporated in the analysis, leading to a more conservative result.