Soil Liquefaction Potential

This research theme focuses on developing and applying probabilistic reliability-based methods to quantify and better capture the uncertainties inherent in soil liquefaction potential evaluation. Traditional deterministic methods often rely on safety factors that do not provide liquefaction probabilities, limiting risk-informed decision-making. Reliability analyses incorporate variabilities in soil properties, seismic loading parameters, and testing uncertainties to estimate liquefaction probabilities, thus enabling more nuanced hazard assessment and engineering design.

This theme explores how intrinsic spatial variability and heterogeneity of soil properties affect the mechanical behavior under seismic loading and consequently the liquefaction potential. Traditional deterministic analyses often assume uniform soil properties, which can underestimate failure probability and liquefaction-induced deformation. Experimental centrifuge studies combined with advanced stochastic numerical simulations investigate how variability in properties such as Standard Penetration Test N-values, shear wave velocity, and internal friction angle modify pore water pressure development and failure mechanisms.

This research area centers on refining liquefaction potential assessment through integration of geotechnical field testing methods such as Shear Wave Velocity (Vs), Standard Penetration Test (SPT), Cone Penetration Test (CPT), and geostatistical mapping tools. These methods offer more direct, continuous measures of in situ soil properties affecting liquefaction resistance. Correlations between Vs, peak strength, soil grading (uniformity coefficient), and cyclic resistance ratios facilitate more accurate identification of liquefiable layers. Spatial interpolation techniques such as kriging enable development of liquefaction potential maps identifying vulnerable zones for infrastructure planning and hazard mitigation.

Research in this theme examines how variations in soil saturation, including partial saturation and induced desaturation, alter liquefaction resistance by modifying pore water pressure generation, matric suction, and volumetric stiffness during cyclic loading. Laboratory cyclic triaxial tests on partially saturated sands demonstrate increased liquefaction resistance compared to fully saturated states. Theoretical interpretations based on equivalent viscous damping and volumetric strain mechanisms explain these effects, suggesting that partial saturation can be a practical mitigation strategy and must be accounted for in liquefaction models.