The Relation Between Support And Surrounding Rock Of Full-Mechanized Caving Mining When The Thick Coal Seam Was Invaded By Layered Lamprophyre

With the increasing depth of coal-mining,plenty of full-mechanized caving mining of thick coal seam over 20m is conducted under the condition of a large area of layered lamprophyre invasion.It has been proved by the production process of practice that traditional theory of mining pressure can no longer guide production for the thick seam that is invaded by layered lamprophyre.The phenomenon of overwhelming supporting are repeatedly encountered when the working resistance of a support which selected according to traditional theory of mining pressure has been improved again.The roof and top coal has changed essentially when the thick coal seam was invaded by layered lamprophyre,which will lead to great difference in structure of overlying strata and movement rule as well as the relation between support and surrounding rock in a mining face.Based on the Analysis on mechanical properties of lamprophyre and metamorphosed coal as well as the structure features of overlying strata in a mining face used full-mechanized caving mining to the thick coal seam,the relation between support and surrounding rock of full-mechanized caving mining when the thick coal seam was invaded by layered lamprophyre is the focus of this paper.Throughout the whole paper,the stress conditions of support and the reason of overwhelming supporting are studied so that the reasonable working resistance can be determined,which will provide important reference value to the mining of the thick coal seam under the condition of layered lamprophyre invasion in order to make project practice carry out efficiently and safely.For the above problems,with the research background of the thick coal seam invaded by layered lamprophyre in the Tashan Coal Mine of Datong Coal Mine Co.Ltd.,adopt the method of combining indoor experiment,theoretical analysis,numerical simulation and similar simulation,the relation between support and surrounding rock of full-mechanized caving mining has been further studied in this paper.(1)Through traditional mechanical experiments,the mechanical properties of lamprophyre and metamorphosed coal as well as the broken bulge of lamprophyre is well studied.Thus,summary has been done on the mechanical and broken properties of lamprophyre together with the difference of mechanical properties between the metamorphosed coal and the tradition coal,then researched the influence of these factors on the overlying strata structure.(2)Integrate obtained experimental data and through theoretical analysis,numerical simulation and similar simulation,the structure of the overlying strata and its mobile laws is the key object of the study.(3)Based on structure of overlying strata and it's mobile laws as well as utilize the theory of rock mechanics,elastic-plastic mechanics and structural mechanics,the mechanical transfer law and deformation instability mechanism of the thick coal seam,witch under the condition of layered lamprophyre invasion and been used full-mechanized caving mining to has been explored,and then the relation between support and surrounding rock together with the working resistance of support can be understood in depth.(4)Using the method of numerical simulation and in-situ rock pressure measured the conclusion of this paper is verified,fully proved the correctness of the conclusions in this paper.The study about the relation between support and surrounding rock can provide theoretical basis and technical support for the full-mechanized caving mining when the thick coal seam was invaded by layered lamprophyre.Since the thick seam which is invaded by the lamprophyre is widely distributed in the domestic,this project will have a wide range of application value and broad application prospects.