Influence of unloading slots on the stressed state and creep of a rock mass in the vicinity of an excavation

The influence of a single unloading slot and several interacting unloading slots on the stressed state and creep of a rock mass adjacent to excavation walls is studied. It is shown that the unloading slots allow us to reduce considerably the intensity of stresses in the vicinity of the excavation, to decrease the concentration of tangential stresses, and to move the zone with high stresses away from the excavation walls deep into the rock mass. It has been found that the use of unloading slots leads to an increase in the wall creep toward the excavation centre.