Mpt-bankm Of Roof Deformation And Its Control In Roadways With Extra Thick Coal Seam

In order to solve the frequent and sudden collapse problem in a large area of the roadway withextra thick coal seam, the roof deformation mechanism of this kind of roadway is studied in detailand a proper and effective controlling technology is put forward. The numerical simulation and insitu observation methods are combined to analyze the deformation characteristics and brokenprocess. The roof abscission reason, occurrence conditions, formation mechanism are thenresearched, and the key influence factors are determined from15influenced factors and a total of50designs in combination with numerical simulation and orthogonal design methods. Acombination support system called “Lots of support structure”(LSS) to reduce the development ofthe roof abscission is proposed, and then the corresponding mechanical models are built to analyzethree structural mechanism inside the roof, and the key parameters calculation formulas such assafety bolt supporting force, pre-tightening force of the cable truss are deduced. The monitoringmethod named “horizontal-vertical crossing”(HVC) and comprehensive index “abscissioncategory”(AC) are respectively proposed. Combined with the in-site monitoring results and AHPanalyzing methods, the roof evolution characteristics in the stage of work face mining, evaluationindex and safety range are obtained, and then a set of roof safety evaluation system is developed inJava language program. The research achieves have been applied to the typical roadways tomonitor or safety verification of the roof supporting and have brought social and finical benefits.