Key technical parameters for roof cutting retained roadways in medium-thick coal seams with hard roof
To determine the key technical parameters for roof cutting retained roadways in medium-thick coal seams with hard roof,we took the transport roadway of No.1026 working face at Jiegou Coal Mine in Suzhou,Anhui,as the engineering example.A mechanical model for hard roof cutting retained roadway was established.In terms of theoretical analysis,numerical simulation,and on-site experiments,we clarified the influence of cutting height,cutting angle,and borehole spacing on the roof cutting.Key technical parameters for roof cutting retained roadway in the transport roadway of No.1026 working face were defined as follows:a cutting height of 10 m,a cutting angle of 0°,and a borehole spacing of 0.5 m.Field measurements demonstrate that the cumulative roof subsidence in the retained section of No.1026 face transport roadway ranges from 170 mm to 250 mm.The hydraulic supports on the goaf side and the solid coal side are 180～200 m behind the working face,with stable pressure,and strong anchor bolts,resulting in a good roof cutting retained roadway condition.The findings of this study provide a valuable reference for determining key technical parameters for roof cutting retained roadways under similar geological conditions.
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