Research Of Filling Strata Movement Laws Of Large Cross Section Roadway Full-mining

In order to solve the problem of surface subsidence and underground water bursting caused by traditional mining methods,a new type of coal mining method,large-section alley-type fully-mining and mining,comprehensive analysis and physical analysis,Similar simulation,numerical simulation and other research methods,the coal mining method of overlying rock movement law and the characteristics of aquifer fissure to conduct a preliminary study and research results for its future engineering applications to provide a reference.The main conclusions are as follows:(1)Through the theoretical analysis,it is found that the coal mining method is similar to the conventional coal mining method.The volume of the roof before filling,the volume of the filling and the amount of the non-joint are the main influencing factors of the overburden movement.And through theoretical analysis,it is found that in the four mining stages,the first and second stage overburden basically does not fall under the development of fracture and bending subsidence,in the latter two stages of the rapid development of cracks,but the roof of the sink or In the controllable range.Based on the theory of elastic foundation,two types of roof movement models are established.According to the relationship between deflection and rotation angle and curvature,the rotation angle and curvature model of two kinds of roof are established respectively.Under the premise of neglecting the weight of the roof and the volume of the filling,the enrichment rate is multiplied by the height of the coal seam.The method of how to predict the height of the aquifer development is put forward.(2)The law of overlying strata under the three stages of mining is studied by physical similarity simulation.It can be found that the displacement of the roof is very small in the early stage of roadway mining,but in the third stage of mining,the amount of roof slump increases sharply.It is therefore possible to show that the final stage of exploitation is a "critical stage" for controlling the deformation of overlying strata.After the third stage of mining,the overburden structure is basically complete without collapse belt,only a small part of the coal seam within the scope of fissure development,overlying rock only occurred in the two zones with two cracks and bending subsidence zone.(3)Through the numerical simulation,the characteristics of overlying strata under four mining stages are studied.It is further confirmed that the "critical stage" of controlling the overburden movement is mainly manifested in the maximum subsidence coefficient of the surface,the maximum sinking of the roof The maximum support pressure and the development height of the aquifer fissure increase with the advance of the roadway,and the increase in the last stage of the mining process is much larger than that of the first three stages.The maximum subsidence coefficient of the overburden parameter,The maximum subsidence amount,the bearing pressure and the aquifer fissure development in the first three mining stages did not change with the change of the filling rate.However,the four types of overburden parameters at different filling rates changed in the fourth stage.The final stage filling rate is the dominant factor controlling the overburden movement,and the maximum subsidence amount of the direct top is approximately negatively correlated with the filling rate.The position of the maximum bearing pressure is determined by the fourth stage of the central stage of the third stage The pillars are transferred to the coal walls on both sides of the stope.(4)Therefore,it can be concluded that the "critical stage" and the filling rate are the main controlling factors for the deformation and deformation of overburden-filled overburden in some areas.In some areas where the geological conditions are very complex and the fragile ecosystems can be retained,"No mining and as much as possible to improve the filling rate and other measures.