Study on the Top Coal Caving and Drawing Controllability in Fully Mechanized Caving Face of Steep Thick Seam
|School||Xi'an University of Science and Technology|
|Keywords||Steep thick seam Top coal caving and drawing controllability Drawing coal technology Water injection weakening|
The horizontal section top coal caving in steep thick seam using fully mechanized caving mining,because the mining structure of space dimensions (variable scale) and other characteristics,the top coal in excavation disturbed zone has obvious tendency to collapse and the dynamic collapse is fast.it easily transformed into overburden medium strength decreases and induced disasters associated with derivatives.If we can not grasp the top coal damage evolution law and not to improve the controllability of top coal,the large horizontal section top coal caving in steep thick seam using fully mechanized caving mining will also be out of the question.In this study the target is safe and efficient mining in the horizontal section top coal caving of steep thick seam using fully mechanized caving mining.First of all combine the domestic and foreign status of steep seam mining technology,through field survey, the horizontal section top coal caving in steep thick seam using fully mechanized caving face regional geology,production and technological conditions.By use of indoor rock physical mechanical properties experiments,we obtain physical and mechanical index parameters of the steep seam and the roof.according to the Physical model of Steep thick seam using fully mechanized caving in WEI Hu-liang mine face,by the use of static resistance strain gauge and acoustic emission technique (acoustic emission, AE) do real-time tracking analysis for dynamic mechanical parameters and their corresponding micro-structure evolution in the process of localization. From the macro and micro aspect revealed the localized deformation-evolve to instability rules in composite coal and rock medium under different mining conditions,and analyzed the working resistance of support which is under the condition of the large section top coal caving.With the large three dimensional similar material simulation experiment results and ellipsoid caving theory,demonstrated steep seam caving and drawing characteristics and analyzed the controllable factors.finally,existing hydraulic support equipment’s compatibility in fully mechanized caving face of WEI Hu-liang mine and interaction characteristics of the“support-surrounding rock”under the greater height of horizontal section conditions are analyzed,demonstrated according to the characteristics of top coal caving and the field experiment reasonable caving parameters was proposed.Aiming at top-coal weakening problems based on the water injection weakening industrial test reasonable water injection weakening technical parameter is determined.Finally formed top coal caving and drawing technology of steep thick seam.The technology had been successfully applied to the production process control in steep thick seam using fully mechanized caving of WEI Hu-liang mining face.The research provides a reliable basis for safe and efficient mining in the horizontal section top coal caving of steep thick seam using fully mechanized caving mining.At the same time, the control technology has a certain referent significance.