Evolution Mechanism of Roof Separation in High Dynamic Pressure Roadways
Based on the principle of elastic-plasticity and fracture mechanics,we analyzed the evolution mechanism of roof separation in the roadways with strong dynamic pressure,estab-lished a mechanical model of a rock beam with fixed supports at both ends,and analyzed five indi-cators reflecting the separation mechanism.The study compares the separation evolution mecha-nisms under high static load and strong dynamic pressure,exploring the symbiotic relationship between interlayer separation and various fracture patterns of the rock beam.Results show that under high geostress and strong dynamic pressure,the roof rock beam undergoes irreversible gradual evolution or catastrophe instability from an elastic state to a plastic or fractured state.The interlayer separation continuously initiates and expands,merging with accumulated damage cracks within the rock layer,which forces the roof into a vicious cycle of"separation-fracture,""fracture-separation,"and"separation-oscillation-shock fracture,"posing significant safety risks.The roof rock beam structure in roadways under strong dynamic pressure must maintain good in-tegrity,large thickness-span ratio,and high strength.Forming a"thick-hard-small"strong load-bearing structure allows the roof rock beam to remain elasticity,control plasticity,and prevent fracturing,ensuring roof structure stability and controllable separation.
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维普
