Particle-scale insight into transitional behaviour of gap-graded materials – small-strain stiffness and frequency response

Masahide Otsubo, Troyee Tanu Dutta, Manushak Durgalian, Reiko Kuwano, Catherine O'Sullivan

Research output: Chapter in Book/Report/Conference proceedingConference PaperOther

1 Citation (Scopus)

Abstract

This study aims to develop a fundamental understanding of the role of fine particles on the small-strain stiffness of gap-graded granular soils. Stiffness was measured using cyclic triaxial probes, which give a measure of static stiffness, and dynamic wave propagation data, from which the dynamic stiffness can be measured. Assemblies of loosely packed spherical particles were considered. In the laboratory, local deformation transducers were used to measure the static stiffness, while the dynamic stiffness was calculated from stress wave velocities, measured using planar piezoelectric elements. To relate the particle-scale responses to the overall soil stiffness, complementary discrete element method (DEM) simulations were performed in which both static and dynamic stiffnesses were measured. Both the laboratory and the DEM data indicate that at low fines contents (< 30%) the stiffness decreases with increasing fines content. When the fines content increases from 30% to 35% there is a sharp increase in stiffness with increasing fines content; this is understood to mark the transition point at which the fines start to contribute significantly to the overall behaviour. Analyses of the frequency domain response of shear wave signals revealed that the lowpass frequency increases significantly at this transition point. This observation can be used to develop experimental interpretation protocols to assess to what extent fines are contributing to the overall soil stiffness.

Original languageEnglish
Title of host publication7th International Symposium on Deformation Characteristics of Geomaterials, IS-Glasgow 2019
EditorsErdin Ibraim, Alessandro Tarantino
PublisherEDP Sciences
Number of pages5
ISBN (Electronic)9782759890644
DOIs
Publication statusPublished - 25 Jun 2019
Externally publishedYes
EventInternational Symposium on Deformation Characteristics of Geomaterials 2019 - Glasgow, United Kingdom
Duration: 26 Jun 201928 Jun 2019
Conference number: 7th

Publication series

NameE3S Web of Conferences
Volume92
ISSN (Print)2555-0403
ISSN (Electronic)2267-1242

Conference

ConferenceInternational Symposium on Deformation Characteristics of Geomaterials 2019
Abbreviated titleIS-Glasgow 2019
CountryUnited Kingdom
CityGlasgow
Period26/06/1928/06/19

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