Abstract: Uniaxial compression experiment is carried out on the cemented waste rock backfill of which the framework particles satisfy Talbol grading theory by MTS815 rock mechanics testing system and homemade device. The influences of Talbol index, initial porosity, type and content of cementitious material on the characteristics of strength and deformation of backfills are analyzed. The results show that the uniaxial compression strength, elastic modulus and deformation modulus of backfill increase first and then decrease with the increase of Talbol index. By adopting the quadratic polynomial to get the relations between the uniaxial compression strength of backfill and the framework grain Talbol index, it is concluded that when the Talbol index n is 0.45, the optimization of the strength and deformation characteristics can be achieved. Uniaxial compressive strength of backfill generally declines as the initial porosity increases and also can be affected by the pore distribution. When the uniformity of pore distribution is poor, it will cause the experimental results some differences. The strength of backfill, which meets the Talbol distribution, will increase as the glued performance of cementitious material improves. Among those materials, the uniaxial compression strength of backfill bonded with cement can be over 6 times higher than that of the specimen bonded with clay. In addition, the strength of backfill can be increased by the content of backfill enhanced. And in this way, the pore compaction stage in its stress-strain curve can be shortened.

Key words: continuous gradation, cemented waste rock backfill, strength, deformation, Talbol index