Mechanical Characterization of Cemented Paste Backfill

Mechanical characterization is important to the design and analysis of cemented paste backfill (CPB) structures. Unconfined compressive strength (UCS) tests have been widely used owing their relative simplicity characterize a material’s response unconfined loading. However, UCS represents single parameter does not fully describe (or failure) envelope. In this study, we analyzed with direct shear uniaxial tensile conducted on same CPB materials provide mechanical under more complete range loading conditions. The results demonstrate Mohr–Coulomb failure envelope provides consistent description strengths arising from three different test methods. Furthermore, better estimate UCS/4, which considerably higher than conventional assumption that equal USC/10 or UCS/12. This has significant impact assessed required particularly for undercut designs using Mitchell’s sill mat method suggests in future should be complemented tension improve underground CPB.