Research On Prevention And Control Of Rockburst In Filling Mining

The traditional mining method has the problem of high concentration of local stress in surrounding rock,and it is easy to cause rockburst.The method of filling mining can effectively reduce the subsidence of coal seam roof,reduce the forward bearing pressure of working face,effectively restrain the occurrence of the rockburst of coal seam and roof,so it is the reasonable method to control rockburst effectively.In order to explore the conditions and influencing factors of rockburst in the stope of filling mining,to verify the effectiveness of filling mining to prevent and control rockburst,to achieve reasonable design filling method and filling process and filling parameters,to lay a theoretical foundation for effective prevention and control of rockburst in backfill mining,and to guide the engineering practice exploration of backfill mining,this paper chooses the Jixian Coal Mine as the Test mine,uses the research method of the theory analysis,the laboratory test,the numerical simulation,the similar material simulation and the engineering practice to combine,carries on the research to the prevention and control rockburst theory and the application.The main contents are as follows.1.Study on the disturbance response instability theory and classification of rockburst.Based on the stability theory of the coal-rock dynamic system,the disturbance response instability theory of rockburst is developed,the instability mechanism is revealed,and the instability criterion of rockburst is established.According to the disturbance response instability theory of rockburst,the classification of Rockburst is studied.2.Study on Rockburst of underground coal rock mass without filling.According to the disturbance response instability theory of rockburst,the paper constructs different types of coal-rock dynamical systems for different types of rockburst without filling,establishes the mechanical model and analyzes it,obtains the main influencing factors,and lays a theoretical foundation for the prevention and control of rockburst.Based on the stability theory of coal-rock dynamic system,the critical conditions and the main influencing factors of different types of rockburst are obtained by establishing the circular section roadway-surrounding rock-supporting system,coal seam-gob-roof system,fault-pillar system and analysis.Based on the model of roof shear beam,the paper studies the characteristics of roof rupture in the process of mining face,the paper puts forward the C-shape plate model of roof fracture,reveals the shear instability mechanism of rockburst induced by roof fracture,and the source of rockburst,and puts forward the basic idea of controlling rockburst of shear failure fracture of roof.3.Study on the filling method for prevention and control of rockburst.Based on the classification and analysis of the filling mining methods,combined with the basic types of rockburst and the influencing factors,the filling mining method for different types of rockburst is put forward.4.Study on the filling materials for the prevention and treatment of rockburst.The filling material and its mechanical properties are analyzed.A concrete filling body with rigid-flexible coupling performance is developed,the lower end is the concrete rigid material,the upper end is flexible material,and the mechanical properties of concrete material,flexible material and combination are tested respectively.As the supporting body of the roadway,the concrete filling body can provide some initial supporting force to the roof,and play the role of cutting the roof,and the flexible filling body absorbs the kinetic energy generated by the roof movement to prevent rockburst.5.Study on rockburst in coal mine under the condition of filling mining.The theoretical analysis structure model of backfill stope and gob-side roadway filling stope is established respectively.The critical conditions and the main influencing factors of different types of rockburst are obtained,and the critical conditions and the influencing factors of different types of rockburst in the stope are compared without filling mine and analyzed.The control effect of filling stope on roof deformation and failure is expounded,in this paper,the theoretical analysis model of rockburst in filling mining is established,the role of backfill in the prevention and treatment of rockburst in filling stope is studied,and the theory of rockburst is established,which verifies the effectiveness of rational filling mining method to prevent rockburst.Through analytical analysis,the limiting conditions for the deformation and stress of the roof,the direct roof,the coal seam and the filling body are obtained.By this restriction condition,the coal seam impact,roof impact and filling body impact may be judged first.The filling mining has effective control effect on different types rockburst.The critical gob width of coal body rockburst during filling mining is about twice times the width when there is no filling.For the deep mining,although the filling body can effectively control rockburst,but still can not completely eliminate rockburst,the need to develop more good materials,improve the strength of the filling body to achieve effective reduction of impact risk.6.Numerical and physical simulation study on the prevention and control of rockburst in backfill mining.To make up for the lack of analytic analysis,numerical simulation of goaf filling stope is carried out using RFPA numerical simulation software,numerical simulation is carried out by using FLAC3D numerical simulation software to study the backfill stope along gob-side roadway,and a simulation test of similar material is used to simulate the filling stope along gob-side roadway.Compared with the simulation results of no backfill stope,it further verifies the effectiveness of the backfill mining in preventing and controlling the rockburst.When the strength and compaction rate of filling body is large enough,the stress concentration of roof is weakened,which can effectively prevent the occurrence of roof fracture type rockburst.The filling body and the coal body bear the mining dynamic stress,and the coal body stress concentration is weakened,which can effectively prevent the coal compression type rockburst occurring.When filling mining,the variation amplitude of fault compressive stress decreases,and the fault is not easy to activate,which effectively controls the occurrence of fault dislocation type rockburst.7.Engineering practice of prevention and control of rockburst by filling mining.This paper chooses Jixian Coal Mine as test mine,and carries out the engineering practice of preventing and controlling rockburst by filling mining.The paper has 160 figures,16 tables and 168 references...