The behaviour of beds of fine-grained sand under fluid wave trains was investigated using centrifuge modelling. Three sets of centrifuge wave tank tests with viscous scaling were performed, such that time-scaling laws for wave propagation as well as consolidation were matched. The test programme consisted of either progressive- or standing-wave tests on loosely packed, fresh deposits of soil, as well as repeated travelling-wave tests with intervening periods of consolidation. The results from the progressive- and standing-wave tests indicate that for each of the wave-loading regimes, there exists a critical cyclic stress ratio below which liquefaction does not occur. The critical value for the progressive-wave-loading series was found to be considerably smaller than that for the standing-wave-loading series. Moreover, the wave-induced liquefaction of the sand beds was of a progressive nature. In fact, under the action of severe travelling waves, liquefaction was first induced in the uppermost layer of the sand bed, and then the liquefaction front advanced downward in the course of wave loading, eventually bringing the entire soil bed into a state of complete liquefaction. It is also shown from the repeated wave tests that the liquefied beds of soil underwent significant densification in the consolidation processes that followed. In each of the subsequent wave-reloading stages, re-liquefaction was observed to occur in such a way that the final depth of the liquefaction front became shallower. Nous avons étudié le comportement ďun banc de sable fin soumis à des trains ďondes fluides en utilisant une maquette centrifuge. Nous avons conduit trois lots ďessais en bac centrifuge avec échelle de viscosité, de facon à lui faire correspondre les lois ďéacchelle de temps šappliquant à la propagation des ondes tout comme à la consolidation. Le programme ďessais consistait de tests ďondes progressives et d'ondes stationnaires passant sur des dépôts de sol frais, non compacté ; le programme comportait aussi des essais répétés ď'ondes progressives avec des périodes intermittentes de consolidation. Les résul- tats des essais ďondes progressives et ďondes stationnaires indiquent que pour chacun des régimes de charges ďondes, il existe un taux de contrainte cyclique critique en dessous duquel la liquéfaction ne se produit pas. On a constaté que la valeur critique pour la série de charges ďondes progressives était bien inférieure à celle de la série de charges ďondes stationnaires. De plus, la liquéfaction des bancs de sable causée par les ondes était de nature progressive. En fait, sous ľaction ďondes fortement progressives, la liquéfaction se produisait ďabord dans la couche supérieure du banc de sable, puis le front de liquéfaction avancait au cours de la charge ďondes, mettant finalement le banc de sol ender dans un éat de liquéfaction totale. Nous montrons également, en nous basant sur les essais ďondes répétés que les bancs de sol liquéfiés subissent une densification significative au cours des processus de consolidation qui solvent. Dans chacun des stades suivants de recharges ďondes, nous avons observé qcune nouvelle liquéfaction se produisait de telle manière que la profondeur finale du front de liquéfaction diminuait.
p. 748, caption for Fig. 1; "Fig. 1. Current systems in the upper layer of Japanese and its neighboring waters (from Kawai, 1991), with notes on geographical distributions of ..." should be read as "Fig. 1. Current system in the western North Pacific in summer (Aug., 1933), originally prepared by Uda (1935), and adapted from Kawai (1972, Fig. 3.2, Forklike currents without confluence), with notes on geographical distributions of ...
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