Research On Structural Characteristics And Dynamic Effects Of Cemented Tailing Backfilling And Its Application

Backfill mining method is more effective than caving method in controlling ground pressure and restraining surface subsidence.Because of its capacity,small loss and dilution and other advantages,this mining method gradually receives the domestic and foreign large-scale mine attention.Due to the continuous slurry ability,it is difficult to complete the one-time filling the huge goaf,which results in obvious structural characteristics of the cemented tailing backfilling(CTB).At the same time,the mechanical properties of the CTB are complicated by the blasting dynamic load during the mining process.In order to reveal the damage mechanism of CTB under the effects of dynamic loading and structural characteristics,this paper adopts the methods of laboratory test,theoretical analysis and numerical simulation to study the mechanical properties of CTB.The uniaxial compressive experiment of CTB was carried out from the structural characteristics such as filling times,filling interval time and filling surface angle.The relationship between the peak compressive strength and the structural characteristics of CTB was quantitatively characterized by different fitting methods.The failure modes of CTB with different structural characteristics were studied.Dynamic experiments of CTB with different loading rates and SHPB impact effects were carried out,which quantitatively characterizes the strength and dynamic characteristics of CTB.The coupling rock and CTB samples(CRTSs)were made,and the uniaxial and triaxial compressive tests were carried out.The relationships of stress-strain,acoustic emission(AE)ringing count and energy change were studied by means of theoretical analysis and numerical simulation.At last,the mechanism of interaction between surrounding rock and CTB was revealed.The theoretical mechanical model of CTB artificial pillar was established by means of semi-inverse method.Based on engineering background of Daye Iron mine,the distribution of horizontal stress and shear stress of CTB pillar was studied.Finally,the control measures of the stability of CTB were put forward.