Study on strong mine pressure behavior and overburden fracture movement law of multi-layer thick and hard roof in Yushen mining area
Aiming at the serious problems of strong mine pressure and gob-side roadway deformation under the multi-layer thick and hard roof in Yushen mining area,the roof overburden fracture and surrounding rock stress characteristics of gob-side roadway under multiple-key stratum structure were analyzed by comprehensively using theoretical analysis,numerical calculation and micro-seismic monitoring methods.The results showed that under the condition of multi-layer thick and hard rock strata,the vertical displacement and energy of roof fracture showed obvious low-medium-high zoning characteristics,and the medium-high-level rock strata fracture lagged behind that of low-level rock strata,which constituted the important structural basis of large-small periods of working face.When the working face was advancing,the large energy micro-seismic events of the broken roof in the adjacent goaf increased,and the breaking strength was higher,causing strong secondary mining influence on the surrounding rock of the gob-side return airway,which was the main causes of high stress and strong deformation of the gob-side return airway.At the same time,the combined breaking of high-low-level key strata could lead to the increase of the strength and risk of large-cycle weighting.Controlling the breaking movement law of key strata roof can be an effective way to reduce the strength and frequency of large-cycle weighting.
multiple key stratalarge and small periodic weightingthick and hard roofoverburden movementmicro-seismic monitoring
万方数据
维普
