Research On The Stability Of Full Tailings Cemented Filling Body Under Lateral Unloading

Green mines is the inevitable choice for the development of mines.Backfill mining is a green method to exploit ore body,and the sublevel open stoping with subsequent filling method is used widely in mines for its advantages.Therefore,it is very necessary to research the stability of filling body in the sublevel open stoping with subsequent filling method.According to the reality in mines,the paper analyzes and researches the stability of full tailings-cemented filling body in lateral unloading,and this is based on rock mechanics test,theoretical analysis and RFPA^3D numerical simulation.According to the interaction of filling body and pillar and wall rock,the interaction mechanism and types are analyzed between them.On this basis,combining the reality of first step mining room and second step mining pillar,the three dimensional mechanical model of filling body is established,and its stress state is main analyzed in two step mining pillar when its side uncovers.Its stress is analyzed based on Terzaghi theory,and the equations of vertical stress is deduced for filling body in different depth.The full tailings-cemented backfill specimens with different cemented sand ratios are made with tailings,and its basic mechanical parameters are tested through compression testing machine.According to the fitting formula of input parameter of RFPA^3D and testing parameter,the input parameter is figured out.Referring to the specimen size in lab to build numerical model,the simulation research is made about lateral unloading of model.Though RFPA^3D to make numerical simulation on the specimens with different ratios,the lateral unloading simulation is made with different lateral stress,and the failure manner of model through fissure extension and connection is analyzed and researched combining with different simulated pictures.According to the simulated result,the failure process is analyzed,and inductive inference is made about the stability.The above research has some scientific reference value to design backfill strength for mine.