Study On Overburden Movement And Fracture Development In Ascending Repeated Mining

The law of overburden deformation and fracture development in coal mining is the key theory of research directions such as water-protecting mining,surfacesubsidence-reducing mining and Coal and gas co-exploitation,and is one of the core theories of green mining.The overburden deformation and fracture development is ever-changing with complex geological conditions and mining conditions.The overburden deformation and fracture development is very complicated in the ascending repeated mining.According to the engineering geological conditions of the ascending mining of Dashucun Mine,the similar simulation research method was used to study the structural changes and deformation and failure characteristics of the interlayer rock in the ascending mining under repeated mining conditions.The analysis shows the characteristics of overlying strata and moving deformation of the overlying key layer under repeated mining conditions.Based on the results of similar simulations,a trapezoidal structure crack propagation model based on key layer theory is established.The formation and distribution characteristics of coal-bearing strata are analyzed.The mechanism of the classification and fracture formation in the rock strata is studied.By the numerical simulation method,the development and evolution characteristics of the overlying repeated mining overlying fractures are obtained.The comparative analysis shows the variation law of the up-series and down-series mining space and the key layer and surface subsidence law.The existence and distribution characteristics of overburden space are analyzed and the mechanical model of the key layer above the separation zone is established by using the elastic foundation beam theory,and the deformation curve of the key layer is obtained.Using the Salamon fractured rock compaction theory,the rock compression characteristics of the fallen area are obtained.The theoretical analysis of the variation characteristics of various overburden space is carried out.Based on the space conservation effect in the process of overburden space transfer,the spatial evolution analysis is carried out.Dissertation includes 55 pictures,6 tables,and 86 references.