2.6 State of stress
In some locations, high in-situ stresses may be present within the rock mass. High horizontal stresses acting roughly perpendicular to a cut slope may cause blocks to move outward due to the stress relief provided by the cut. High horizontal stresses may also cause spalling of the surface of a cut slope. The stored stresses is most likely be relieved to some degree near the ground surface or perpendicular to slope walls.