Experimental study on confined consolidation on different lime sand ratio of backfill body

The backfill body is surrounded by surrounding rock in the stope, and its mechanical properties are different from those under laboratory uniaxial compression.In order to study the mechanical properties and laws of the backfill body, the grading uniaxial compression consolidation test of different lime sand ratio backfill body under confined constraints was proposed.The classification pressure are 1 kN (0.2 MPa), 2 kN (0.4 MPa), 4 kN (0.8 MPa), 8 kN (1.6 MPa), 16 kN (3.2 MPa), 32 kN (6.4 MPa), 64 kN (12.8 MPa), and 128 kN (25.6 MPa).The test results show that the final compression of the backfill body increased linearly with the increase of the consolidation pressure, and the effect of the lime sand ratio on the compression volume of the filling body is not obvious.The consolidation stress and the compression ratio are in a quadratic function curve relationship.The uniaxial compressive strength of the packed body before and after consolidation increased significantly, and the increase in strength at 28 days is more than 24%.The consolidation strengthening mechanism of the backfill body is analyzed by SEM.