Using geophysical data to quantify stress-transmission in gap-graded granular materials

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Title: Using geophysical data to quantify stress-transmission in gap-graded granular materials
Authors: Otsubo, M
Kuwano, R
O'Sullivan, C
Shire, T
Item Type: Journal Article
Abstract: The behaviour of gap-graded granular materials, i.e. mixtures of coarse and cohesionless finer grains having a measurable difference in particle size, does not always confirm to established frameworks of sand behaviour. Prior research has revealed that the role of the finer particles on the stress-strain response, liquefaction resistance, and internal stability of non-cohesive gap-graded soils is significant and complex, and highly dependent on both the volumetric proportion of finer particles in the material and the coarse-particle to finer-particle size ratio. Quantifying the participation of the finer particles on the stress transmission and overall behaviour is central to understanding the behaviour of these materials. However, no experimental technique that can directly quantify the contribution of finer particles to the overall behaviour has hitherto been proposed. This paper explores to what extent the participation of finer particles can be assessed using laboratory geophysics, recognizing that granular materials act as a filter to remove the high frequency components of applied seismic / sound waves. Discrete element method simulations are performed to understand the link between particle-scale stress transmission and the overall response observed during shear wave propagation. When the proportion of finer particles is increased systematically both the shear wave velocity (VS) and low-pass frequency (flp) increase sharply once a significant amount of the applied stress is transferred via the finer particles. This trend is also observed in equivalent laboratory experiments. Consequently, the flp–VS relationship can provide useful insights to assess whether the finer particles contribute to stress transmission and hence the mechanical behaviour of the gap-graded materials.
Issue Date: Jul-2022
Date of Acceptance: 4-Dec-2020
DOI: 10.1680/jgeot.19.p.334
ISSN: 0016-8505
Publisher: ICE Publishing
Start Page: 565
End Page: 582
Journal / Book Title: Geotechnique: international journal of soil mechanics
Volume: 72
Issue: 7
Copyright Statement: © 2021 The ICE. Original article available at Permission is granted by ICE Publishing to print one copy for personal use. Any other use of these PDF files is subject to reprint fees.
Keywords: Geological & Geomatics Engineering
0905 Civil Engineering
0907 Environmental Engineering
0914 Resources Engineering and Extractive Metallurgy
Publication Status: Published
Online Publication Date: 2021-01-26
Appears in Collections:Civil and Environmental Engineering
Faculty of Engineering