Long Qiao Iron Ore Zone Move Roof Rock Caving Characteristics And Coating Thickness Measurement

Sublevel caving without sill pillar will form a large-scale goaf, the roof of goaf movement directly related to the safety in lower section mining. So it must be research the movement and caving characteristics of roof in goaf, analysis the roof caving hazards, ensure the safety mining. Therefore, this article combined with long-term topic "Long-qiao iron ore the goaf monitoring and rock caving law research", using the numerical simulations, theoretical and field monitoring means, around the roof of goaf movement, caving characteristics and the cover layer measurement and analysis, the conclusion of the study show:With the ore mining, the roof of goaf will gradually appear tensile stress, its size and range will increases ceaselessly; under the tensile stresses, the roof more prone to damage, formation fracture, while the original crack and other weak structural plane will be further developed; under the action of gravity, the roof constantly sinking.The original weak structure plane and the new fissures will cut the roof of goaf. By the fissure deformation energy and the action of gravity, block rock mass fissures along the structure surface falling into empty area by the effect of "net sliding force". goaf caving morphology is consistent with natural pressure arch, but this vaulted arch height will continue to change. Use the borehole camera technology monitoring and analysis to explore the fissures on the roof rock, development, and until the block-shaped rock caving, indicated by monitoring roof falling process for falling-stability-in caving and cycle stability.Analysis the roof of goaf caving the impact of the blast hazards and rock layer covering the subtractive effect; use the geological radar measure the rock layer thickness, and application of the monitoring data analysis drilling covering layer thickness, the results show that cover thickness achieve two layer thickness, to ensure the safety of the underground work.This study analysis the roof movement and caving characteristics in sublevel caving without sill pillar. Measure and analysis the rock layer thickness and effectation, to ensure-safety and efficiency of the recovery LongQiao iron ore mine resources provide technical support, as well as mine-like exploitation of a certain reference value.