Research On The Motion And Failure Regulars Of Overlying Strata Induced By Fully Mechanized Caving Faces Under High-position Thick Hard Strata In Guo Jiahe Coal Mine

Linyou mining area is another large mining area to be developed at Huanglong coal base.Guo Jiahe Coal Mine is the main mine which has been put into production in the Lin You mining area,coal seam buried depth,minin,g thickness.There are two hard sandstone with a thickness of about 30m in the 94.93m and 309.69m positions above the coal seam.These rock stratums belong to the high-position thick hard strata which play a major role in controlling the strata behaviors and ground movement and deformation.The practice of field production shows that:The overlying strata will motion with large area when high-position thick hard strata breaking,which causes a strong pressure in working face,and this seriously threatens mine production and personnel life safety.Therefore,the motion and failure regulars of overlying strata under high-position thick hard strata Guo Jiahe Coal Mine is studied,and it has important guiding significance for the safe and efficient exploitation of coal resources in the Linyou mining area.This paper takes the coal mining of Guo Jiahe Coal Mine as the object of research.Based on the analysis of the overburden rock lithology and structure,the hard rock stratum is calculated by key stratum theory.Combined with the definition of high-position thick hard strata,the NO.5 sub key stratum from the roof 94.93m and the main key stratum from the roof 309.69m all belong to the high-position thick hard strata.The physics similar material simulation have shown that:the NO.5 sub key stratum is the main control strata for stope overburden structure stability,and there is a high load structure above the NO.5 sub key stratum.The results of UDEC numerical simulation show that:the interval of roofing breaking of NO.5 sub key stratum and control of overburden range by coal pillar are linearly related to the width of coal pillar.When the coal section pillar size is different,the high structure of overlying rock is different.Using the thin plate theory,the mechanical model of high-position thick hard strata is established.The breaking form and breaking condition of high-position thick hard strata are analyzed,at the same time the influence of section coal pillar on interval of roofing breaking of NO.5 sub key stratum is analyzed.The motion and failure regulars of overlying strata under high-position thick hard strata in Guo Jiahe Coal Mine is obtained.The research results of the paper h,ave important guiding significance for the study of the pressure and surface subsidence of the mine working face in the Guo Jiahe Coal Mine and the same geological conditions in the Linyou mining area.