Study On Microstructure Evolution And Strength Model Of Cemented Filling Body

The backfilling support for stope can solve the problem of ground pressure well,ensure the high rate of underground operation and reduce the deterioration of natural ecological environment.Therefore,it is necessary to study the microstructure evolution and strength model of cemented filling body.The strength of cemented backfill with cement-sand ratio of 1:6,1:8 and 1:10,slurry concentration of 65%,70%,age of 7 days and 28 days was tested.The structure evolution law and strength model of cemented backfill were studied by means of electron microscopy and particle flow software PFC.Based on the strength test of cemented backfill,scanning electron microscopy of the micro-morphology of cemented backfill,and the mechanical characteristic curves of cemented backfill in different proportions,concentrations and ages,the essence of its influence on the mechanical properties of cemented backfill,the quantity and morphology of cemented products in the sample are analyzed.The mechanical properties of cemented backfill are affected.The strength curves of specimens with lime-sand ratio of 1:6,concentration of 70% and age of 28 days were used to obtain of the numerical simulation specimens.The influence of sensitivity and meso structure failure mode is analyzed.The essence of the specimen destruction is that the number of internal bond failure changes to qualitative change.The failure of numerical simulation specimens can be divided into three stages: linear elasticity,bond failure propagation and failure.When the number of bond failure increases rapidly,it is a predictive criterion to judge that the specimens will reach the peak stress.The correlation coefficient between theoretical curve and numerical simulation curve is 0.9792.The study of micro-structure evolution law and strength model of cemented filling body can predict and guide the design of cemented filling body strength to a certain extent,which has far-reaching significance for improving economic benefits of mines and ensuring the surrounding ecological environment of mining areas.Figure 24;Table 10;Reference 66...