Resolution of Acting Forces
Forces acting on a rock wedge (weight of rock wedge, external load, anchor force) are resolved into directions normal to planes A1 and A2 (the block is wedged in between these surfaces) and into the direction of their intersection. The resolution of forces results in the normal forces N1, N2 acting on planes A1 and A2, resisting (passive) forces Tres1, Tres2 acting along planes A1 and A2.
This step further generates the shear (active) force Tact acting in the direction of the line of intersection of slip surfaces. The resulting shear (active) force Tact is obtained as a sum of individual shear forces Tact,i.
The resisting (passive) forceTres is found by summing up the components Tres1, Tres2 (e.g. due to external load) and friction forces on planes A1 and A2 due to normal forces:
cohesion on slip surface A1
cohesion on slip surface A2
angle of internal friction on the slip surface A1
angle of internal friction on the slip surface A2
resisting forces on slip surface As
resisting forces on slip surface A2
Space resolution of self-weight of earth wedge W