Investigation on the Pressure Relief and Roadway Support by Segmented Hydraulic Fracturing Technique in Hard Roof of Fully Mechanized Mining
Targeting the issue of surrounding rock deformation in the 11205 working face groove of Fujiawa Coal Mine caused by the mining-induced effect from adjacent working faces,the causes of mining pressure manifestation and the hydraulic roof cutting pressure relief mechanism was analyzed,using hydraulic fracturing as a pre-treatment measure to alleviate mining induced stress in coal mines was proposed,and on-site industrial experiments were conducted to verify the effect of roof cutting pressure relief.The results demonstrate that hydraulic fracturing effectively weakens the strength of the hard roof and reduces mining pressure manifestations.Observations of the roof reveal that the number of cracks within the borehole walls increases significantly after fracturing,indicating a favorable fracturing effect.By setting up monitoring points in the transportation groove of the 11205 fully mechanized working face,field monitoring data show that deformations of the roadway roof and two sides are reduced by 54％and 50％,respectively.Additionally,the roof stress decreases from 30 MPa to 17 MPa,confirming the effectiveness of the fracturing-induced weakening.The directional segmented hydraulic fracturing technique can effectively reduce the mining-induced stress impact on the protective coal pillar.
Hard roof of fully mechanized miningHydraulic fracturingNumerical simulationPressure relief and roadway support
万方数据
维普
