Study On Overburden Movement And Stress Evolution Law In Deep Mining Height Face

Deep and thick coal seam mining will occupy a very important position in our country's future coal production,and deep large mining height comprehensive mining is an inevitable trend of deep and thick coal seam mining in our country.Therefore,the study of the overburden movement and stress evolution law of deep large mining height mining yards is not only of practical significance for guiding deep mining to adopt large mining height fully mechanized mining,but also can lay a foundation for deep compound dynamic disaster risk assessment.The thesis is based on the geological conditions of the 24030 deep mining height working face in Pingmei No.11 Mine.Through the theoretical analysis,two-dimensional similar material simulation and UDEC software simulation,the movement and stress evolution of the overlying rock layer in the deep mining height mining yard The law of the has been studied,the main results are as follows:(1)Using the key stratum theory and beam theory,the load of the overburden layer on the24030 working face,the initial collapse step and periodic collapse step of each rock layer,and the amount of subsidence at the position of the key layer are calculated,and new The correction formula suitable for estimating the height of collapsed zone and fissure zone under the condition of deep mining in flat coal.(2)A large-scale two-dimensional similar material model test of 24030 working face was established,describing the law of destruction of overlying rock movement and the final distribution characteristics of the "three zones" and settlement law of overlying rock at the deep mining height,and analysis of the working face The law of spatiotemporal evolution of stress in overlying rock layers.(3)Using UDEC software to establish the mining model of 24030 working face,obtained the movement law of overlying strata and the height distribution of the "three zones" after mining,and analyzed the stress evolution law and stress distribution characteristics of overlying strata and the plasticity of overlying strata Distribution pattern.(4)On the basis of the stress arch theory,the stress concentration mechanism of the overburden strata on the working face of deep mining height is analyzed,several factors affecting the change of overburden stress are analyzed,and several deep mining stopes are proposed The principle that the overburden support should follow provides certain theoretical guidance for the safe production of deep mining heights.There are 22 pictures,8 tables and 76 references in this paper.