Minimum strength required for resisting cyclic softening/failure of cemented paste backfill at early age

This paper attempts to assess empirically the liquefaction susceptibility of cemented paste backfill (CPB) at early age (£ 7 days). Early age CPB can be categorized as a “clay-like” material because their plasticity index, PI ³ 5 (PI = Liquid Limit, LL – Plastic Limit, PL). For clay-like material such as CPB, the liquefaction susceptibility can be characterized by the “cyclic softening” or “cyclic failure” which is assessed using an empirical method developed for clays and clay-like materials. This analysis allowed determining the minimum undrained shear strength required to resist cyclic softening (failure) of cemented paste backfills which is directly related to the unconfined compressive strength (UCS).