Study On The Stability Of Inclined Roadway Within Overburden Rock Under Mining

After underground valuable minerals mined，the variation of stress field anddisplacement field of overlying strata should be caused inevitably，and the stability ofroadways within overburden rock under mining would be affected consequently.Therefore，finding out the laws of movement&deformation and stress distribution andstructure evolution of overburden rock under mining，will help to predict the effectextent and the influence range of the roadway in advance and establish reasonablemaintenance&reinforcement measures of the roadway.In this thesis，it was considered the background for our model that the uphillroadways situated in the fifth coal-seam of east area of the tenth mine would be underthe influence of the mining of the sixth coal-seam of the12th mine of Pingdingshan.Based on the method of similar material simulation test，the variation laws of stress fieldand displacement field of overburden rock under the mining of the sixth coal-seam werestudied，then the deformation&damage of surrounding rock along the horizontal&vertical direction of the uphill roadways was analysed.In the process of simulation test，the hydrodynamic simulating coal-seam mining device of constant pressure has beendesigned for improving the methods of simulating coal-seam mining，and the commondigital photographic measurement techniques was developed for enhancing theprecision of displacement observation，and the results proves that good effect wasobtained.The evolution mechanism of crack in overburden rock under mining was analysedon the basis of the similar material simulation，and the extent of damage of overburdenrock under mining was studied quantitatively by using the fractal geometry and theharm mechanics theory，and then the stability of roadways was discussed.Through theanalysis of the deformation&damage law of surrounding rock of dynamic pressurizedroadway and its influencing factors，the supporting strength of roadways was calculatedtheoretically according to the elastic-plastic supporting theory.The results show that themining of the sixth coal-seam of the12th mine of Pingdingshan is finished，the roadwayon which it has little effect above mining face will be within the curve subsidencezone.The fractal dimension of the fifth coal&rock seams is less than1，and the harm variable less than0.5，therefore，as long as appropriate reinforcement and restoration areimplemented to the roadway having been seriously influenced on，its normal use couldbe guaranteed.Based on the analysis of the observation on the spots，the movement&deformationof surrounding rock of roadways was not too much，but the roof cracks of roadwayhaving been seriously influenced on mostly developed，and the coal-seam of theroadway’s sides was extruded.At the same time，it verified the rationality and reliabilityof the results of the similar material simulation test.