Study on failure mechanism of advance effect in fully-mechanized caving face under super-thick and hard rock
Taking the Yima Coalfield in Henan Province as the engineering background,where there is a super-thick and hard rock fully-mechanized caving face,field measurement,theoretical analysis,numerical modeling and other methods were used to investigate the fail-ure mechanism of the advance effect on the working face during mining,corresponding prevention and control strategies were put for-ward.The study shows that the fundamental reasons for the failure of the advance effect are the vulnerability of thick soft rock in lower layer,the integrity of super-thick and hard rock in high layer,the advanced high-strength pressure relief.The thick soft rock in the lower layer collapses immediately with pushing-mining,the overburden's gravity stress that is borne by the coal mass under the strata on which the overall static load acts is homogenized when the super-thick and hard rock in the high layer does not reach the limit span,thus resulting in the lack of obvious advance effect.The advanced high-strength pressure relief not only blocks the transmission path of force,but also reduces the degree of stress concentration.Based on this,it was proposed to design a reasonable pushing-mining length,leave a reasonable isolation coal pillar to reduce the generation of distant suspended rock layers,and implement a prevention and control strate-gy of advanced strong unloading pressure drop force in the near field.It is of great significance for the prevention and control of rock burst because it will greatly reduce or eliminate the impact of advanced effect on the working face under super-thick and hard rock.
super-thick and hard rockfully-mechanized caving faceadvance effectfailure mechanismrock burst
万方数据
维普
