Rayleigh-wave-induced liquefaction in granular soils: micromechanical insights

The micro-mechanisms of soil liquefaction triggered by Rayleigh waves and the implications for current liquefaction assessment practice are of considerable interest, yet remain much less studied than those associated with shear wave-induced liquefaction. This paper presents an investigation into the response of K 0 -consolidated sand-fines mixtures subjected to a series of Rayleigh-wave-induced strain paths using discrete element simulations. The influence of loading path, fines content, and void ratio on the stress–strain response and microstructural evolution are systematically examined. Results show that loading paths dominated by pure shear promote rapid development of fabric anisotropy and significantly reduce liquefaction resistance. However, the influence of loading path progressively diminishes with increasing fines content. At the particle scale, increasing fines content leads to lower coordination number and more pronounced fabric anisotropy, both of which contribute to increased liquefaction susceptibility. For each Rayleigh-wave loading condition, the state parameter exhibits a unified exponential relationship with the stress-normalized dissipated energy required for liquefaction, independent of fines content and K 0 value. These findings provide new micromechanical insights into Rayleigh-wave-induced liquefaction and highlight the effectiveness of a state-dependent energy-based framework for evaluating liquefaction potential under seismic loading.