Stability threshold for cyclic loading of saturated clay

This paper presents the results of an experimental investigation performed to study the stability threshold under cyclic (repeated) loading, and the postcyclic static strength of a sensitive clay from the Hudson Bay region. The strain rate and structure effects were also studied by carrying out mono...

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Bibliographic Details
Published in:Canadian Geotechnical Journal
Main Authors: Lefebvre, Guy, LeBoeuf, Denis, Demers, Benoît
Format: Article in Journal/Newspaper
Language:English
Published: Canadian Science Publishing 1989
Subjects:
Online Access:http://dx.doi.org/10.1139/t89-013
http://www.nrcresearchpress.com/doi/pdf/10.1139/t89-013
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Summary:This paper presents the results of an experimental investigation performed to study the stability threshold under cyclic (repeated) loading, and the postcyclic static strength of a sensitive clay from the Hudson Bay region. The strain rate and structure effects were also studied by carrying out monotonic and cyclic triaxial tests at both slow and rapid strain rates or frequencies, and at confining pressures above and below the apparent preconsolidation pressure. The stability threshold for both structured and normally consolidated Grande Baleine clay is about 60–65% of the original undrained shear strength measured at the same strain rate as that used in the repeated loading test. The undrained shear strength and the failure envelope remain essentially unchanged if the repeated preloading is kept below the threshold. The clay structure remains unaltered by this preloading. Key words: clay, stability threshold, cyclic loading, earthquake, postcyclic strength.