Insights into the assessment and interpretation of earthquake-induced liquefaction in sands under different degrees of saturation

Earthquake-induced liquefaction is a prominent and impactful natural hazard responsible for substantial economic losses worldwide. Hence, engineers and researchers are currently interested in developing methods and techniques to mitigate this destructive phenomenon. Reducing the degree of saturation is a reliable method to improve the liquefaction resistance of sandy soils since it directly influences the pore pressure build-up during seismic action. This paper reviews the mechanisms and assessment of earthquake-induced liquefaction in sandy soils with various degrees of saturation, a crucial parameter for reducing the phenomenon triggering. In addition, it presents novel approaches that delve into interpreting cyclic behaviour with diverse degrees of saturation using stress-based and energy-based approaches. The experimental results compiled and discussed show that, effectively, reducing the degree of saturation holds promise as a viable strategy for enhancing soil liquefaction resistance and mitigating associated risks. Moreover, the interpretation of cyclic behaviour addressed in this paper offers valuable insights into the reliability of interpreting methods to quantify the liquefaction resistance under several degrees of saturation (that may be achieved by desaturation or induced partial saturation techniques), contributing to strategies for resilience against earthquake-induced damages.