Dynamic Properties and Liquefaction Resistance of Fine Coal-Mine Discards

This paper presents the results of an experimental investigation into the cyclic and postcyclic behavior of fine coal-mine discards (FCDs), with specimens sourced from a legacy coal mining area in South Wales, UK. A series of stress- and strain-controlled cyclic triaxial tests on saturated specimens were conducted to examine the influence of confining pressure, cyclic stress ratio (CSR), particle breakage due to compaction, and excitation frequency on the cyclic response and dynamic properties of the FCD. The results indicate that the cyclic response of the tested mining waste geomaterials is primarily controlled by the CSR, with no signs of liquefaction or failure observed at CSR values below 0.15. Additionally, the degradation of shear modulus was found to be nonlinear and highly sensitive to cyclic shear strain and particle breakage. However, no significant correlation was observed between initial particle breakage (breakage potential) and damping ratio.