Study on mechanics mechanism of overburden breaking under periodic weighting of hard roof
The migration law of hard roof breaking has always been a hot topic in the field of mining research.In response to the prob-lem of unclear distribution of breaking cracks inside the overburden,the key blocks in the theory of masonry beams were taken as the re-search object,the model of a cantilever beam under the linear supercharged load was established.According to the inverse solution of stress in elastic mechanics,on the basis of Airy stress function satisfying the biharmonic equation,the analytic solution of internal stress component satisfying the model stress boundary conditions was derived and verified by superposition principle.The Mohr-Coulomb yield criterion was used as breaking criterion,and the breaking trace implicit function equation was deduced.The breaking trace was obtained by MATLAB software calculation and drawing.By examples the rule for the influence of the rock cohesion,the internal friction angle and what on the breaking trace was verified and analyzed,and the correctness of the solution for the fracture trace was verified.It has certain significance for further understanding of the mechanical mechanism of oveburden fracture.
hard roofoverburden breakingperiodic weightingstress fieldkey layer
NETL
NSTL
万方数据
