Control Mechanism And Technology Of Roadway With Lamellar And Coal-rock Interbedded Roof

When roadway roof is composed of lamellar coal-rock interbedded layers, and theinterbedded roof not only possesses the characteristics of relatively poor stability andlow strength, but also is apt to separate and fall, roadway instability resulted from thedeformation and failure of the roof is already one of the key problems that need to besolved urgently.The present paper puts forward the conception of lamellar coal-rock interbeddedroof according to its engineering geology and instable failure features of roadway. Thepaper also uncovers the internal mechanism of intensity weakening of lamellarcoal-rock interbedded roof under the effect of water through the study of the dirt bandcomponents in interbedded roof and its micro-structural characteristics.This paper not only establishes combined beam elastic-plastic mechanicalanalysis model of lamellar interbedded roof, grasps the stress distribution regularity ofinterbedded roof, but also combines the thin-tabular mechanical model with it toresearch the maximum bending deformation and the critical value of horizontal stresswhen roof’s yielding failure happens in two different boundary conditions, acquires thecalculating formula based on span to depth ratio to judge whether the roof fails or not.The paper proposes the criteria to distinguish roof separation determined by limit spanon the basis of the effects the position, number of layers, and thickness of dirt band hason the roof stability.Physical simulation test of similar material is adopted to research the impacts thatoblique rectangle section, round arch section and angle of coal seam have on thestability of lamellar coal-rock interbedded roof. The consequences indicate that integralroadway stability of round arch section is relatively well, and deformation failure is aptto take place in the oblique rectangle section roadway resulted from asymmetry ofsliding of roof rock structure.This paper studies the influence the roadway section has on the lamellar roadwayroof with the application of FLAC3D, contrasts and analyzes deformation failurecharacteristics of lamellar roadway roof in the condition of water and non-water. Basedon the technology of monitoring surrounding rock’s dynamic failure process in themethod of drilling detection, this paper presents technical system of long-term stabilitymonitoring of lamellar roof which treats relation between the excavating time, spatial ofroadway and internal fracture development as a core. The research results are applied in the Laoshidan mining, and earn favorable technical and economic effects.