Abstract: In order to study the influence of the ratio of block tailings on the secant modulus of the blockstone tailings cemented backfill,the specimens with different ratio of block stone tailings were prepared,and the characteristics of secant modulus of the blockstone tailings cemented backfill were analyzed.The results show that the secant modulus of filling body increases firstly and then decreases with the increase of the ratio of block tailings.When the ratio of block tailings is 7∶3,the secant modulus of the blockstone tailings cemented backfill reaches the highest.Afterwards,the secant modulus of filling body begins to decrease with the increase of the ratio of block tailings.When the ratio of block tailings is less than 7∶3,the relationship between secant modulus enhancement factor and the ratio of block tailings shows an exponential function.

Key words: The blockstone tailings cemented backfill, The ratio of block tailings, Secant modulus, Enhancement factor