Improvement of cyclic liquefaction resistance induced by partial saturation: An interpretation using wave-based approaches

• Published in: Soil dynamics and earthquake engineering (1984) 2023-04, Vol.167, p.107819, Article 107819
• Main Authors: Molina-Gómez, Fausto, Viana da Fonseca, António, Ferreira, Cristiana, Caicedo, Bernardo
• Format: Article
• Language: English
• Subjects: Laboratory tests; Liquefaction; Partial saturation; Sands; Wave propagation
• ISSN: 0267-7261; 1879-341X
• DOI: 10.1016/j.soildyn.2023.107819

Methods to estimate the liquefaction resistance in sandy soils have been proposed in the literature, involving correlations between cyclic resistance ratio and seismic wave velocities measured by in situ and laboratory tests. However, the applicability of these correlations has not been validated in sands improved with the induction of partial saturation. This study addresses the assessment of cyclic liquefaction resistance improvement induced by partial saturation using wave-based approaches. For this purpose, an experimental plan comprising cyclic triaxial and bender elements was carried out in a Portuguese natural sand. The studied soil is TP-Lisbon sand, a historically liquefiable soil collected in the ‘Terreiro do Paço’ site — next to the Tagus River in the centre of Lisbon. Notwithstanding, the results presented herein are compared against other liquefiable sands from Japan. The induced partial saturation was controlled by P-wave velocity measurements, which were contrasted against theoretical predictions performed in the light of Biot’s theory. The results confirmed the increase in liquefaction resistance by inducing partial saturation. Experimental results revealed that P-wave velocity provides a reliable prediction of liquefaction resistance in partially saturated conditions rather than S-wave velocity. The suitableness of these approaches was attributed to the presence of occluded air bubbles in partially saturated soils, which can be detected by the P-wave and not by the S-wave. •Advanced experimental results from cyclic triaxial and bender element tests.•Liquefaction resistance assessment in partially saturated conditions.•Results interpretations using wave-based approaches.•S-wave based approach unable to adequately predict the liquefaction resistance of partially saturated sands.•P-wave based approach provides a reliably estimating of liquefaction resistance of partially saturated sands.