Plane Slip Surface
Failure on the plane slip surface is manifested by a rock block sliding down along this surface. The rock wedge can be specified with a tension crack. The solution procedure of stability requires determination of the normal force N acting on the slip surface, the shear force Tact (active) and the resisting shear force Tres (passive).
Forces on the slip surface
The shear strength parameters and the normal force N acting on the slip surface are the main input data for the determination of the resisting shear forces Tres. Calculation of the active shear force Tact and the normal force N is further influenced by the own weight of block (depends on the geometry and unit weight of rock), anchorage, surcharge, influence of water and seismic effects. The active force Tact and the normal force N are determined as a sum of all forces entering the analysis.
The program offers several types of plane slip surfaces: