Strata Behavior Of Ultra-close-multiple Coal Seams Undergob In Fully Mechanized Caving Face And Its Control

Based on strata behavior problems occurred in fully mechanized caving face of Xinyangmine with complicated production and geological conditions, this paper conducted research onstrata behavior law and its control technique of ultra-close multiple-coal seams under gob. Themain research contents are stated as follows: firstly, we established support-surrounding rockmechanical model of fully mechanized caving face with serial complex consists of Maxwellbody, Nishihara body and ideal elastic-plastic and investigated the relation between support andsurrounding rock as well. Then, we established structure mechanical model of second fracture inlower main roof and first fracture in upper main roof, and also illustrated the forming mechanismof large and small cycle pressure. Besides, we established spatial mechanical model of supportloading ability of four-pillars and two-pillars fully mechanized caving support and obtained itsexpression. And, we revealed the loading ability excellence of four-pillars support thantwo-pillars support in the same leaking degree. In addition, we built mechanical model of keyblock B stability and the3D numerical model of abutment pressure distribution, and determinedthe prior observation area of support. Furthermore, we put forward the key control index andclassified fault detection technique, which effectively solved the control problems ofsupport-surrounding rock in102fully mechanized caving face.