Study On Performance Of Cemented Backfill Materials With Unclassified Tailings And Stability Of Stope Surrounding Rock In Yongping Copper Mine

For open-cut and underground combined mines,there exits a mutual interaction and interactive relationship between open-cut and underground mining.The blast wave and rock mass displacement in underground extraction or mining not only influence underground stope,but also the open-pit slope,mining equipments and structures.In order to ensure safe production of Yong-ping copper mine,based on the preliminary design and the data of the experimental stope,the combinations of filling materials were optimized through laboratory experiments of rock mechanics,theoretical analysis and numerical simulation.Then the failure mechanism and stability was studied by non-linear mathematics method.The main content of this paper is as follows:(1)The geological conditions of Yong-ping copper mine was investigated and studied from the respect of stratigraphic,geological structures,ore body geostress characteristics;(2)The rock mass mechanical parameters were tested in laboratory.Mainly includes:density and moisture content determination,compression tests,split tension tests and shear tests,which build a basis of subsequent analysis and mathematical modeling;(3)The granularity and physicochemical parameters were estimated in laboratory.To get the optimum ratio of the composite cementing material,homogeneous design experimental project was built based on MSE criteria.By multiple stepwise regression method,the optimal strength solution of the backfill material was determined.Then the influencing degree of single factor was analysed using path analysis method.In the last,the reliability of the regression model was validated;(4)In order to explore the intrinsic linkage of the P-wave velocity and the stresses distribution of the rock,a mathematical model between them was established based on the elastic media fluctuation theory and the reliability of the model was validated based on the experimental data;(5)The acoustoelastic character of the rock during loading process was analyzed based on catastrophe theory and the catastrophe point was obtained.According to the data,the rock damage mechanism was studied;(6)The discriminants of catastrophe potential function(four times and five times Taylor's expansion)were deduced based on the cusp catastrophe theory.The energy criteria was redevelopment in FLAC3D based on FISH language.The numerical simulation model of fillings-beam system was established and the safety factor of the system was calculated by using strength reduction-catastrophe theory.