Mechanism and control strategy of buckling rockbursts of orthotropic slab

Brittle slabbing failure of deep highly-stressed hard rocks exists in engineering geology and mining engineering extensively, and the slab buckling rockburst induced by slabbing failure also brings severe challenge to safe and high-efficient excavation of deep resources. In order to analyze the mechanism and control strategy of slab buckling rockbursts of high-stressed hard rocks, a mechanical model for orthotropic thin plate is established for slabbing rockmass, and the critical load of slab buckling rockburst under two-dimensional stress condition is also deduced. The deflection value under buckling is calculated according to the energy method on the basis of acquiring the bending deformation potential energy. The filling method, deemed as the control strategy, is proposed to prevent slab buckling rockbusts, and the rational confining pressure is deduced accordingly. The research results indicate that (1) For those phenomena of slab buckling rockbursts which occur in vertical layered rock mass, it is necessary to establish a mechanical model for orthotropic thin plate for slabbing rockmass when proceeding the relevant mechanical analysis; (2) The increase of axial stress promotes the formation of slabbing and intensifies the possibility of slab buckling rockbursts; (3) The horizontal deflection value, within a certain range, may increase with the decrease of plate thickness under buckling, and has the maximum value when the length-to-height ratio of thin plate is equal to ; (4) A relatively low confining pressure value can prevent the occurrence of slab buckling rockbursts when adopting the filling method in deep engineering.