Immediately,after creation of the first line of pillars in direct vicinity of the rock mass,the pillars are loaded with pressure induced by exploitation and because of their appropriate small dimentions,transit from precritical to postfailure stage of work.
As a result,when the mining front line is moving ahead, the partially destroyed pillars in the exploitation field must still support the roof and assure stability of the rooms.
Their ability to accumulating energy is significantly decreased.