ELFT HÍRADÓ

[Van Peter <vpet AT phyndi.fke.bme.hu>]

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November 23. kedd, 15.30
ELTE, TTK, Pazmany P. setany 1/A, 3. em. 3.114 (3.95) terem

John McDougall, School of Built Environment, Napier University,
Edinburgh, Scotland

Decomposition and its description in soil-like materials

Abstract:
When soil-like or particulate materials decompose, there is a
reduction in solid phase volume and an induced change in void
phase volume, the combination of which has consequences for
subsequent mechanical behaviour. In the case of landfilled waste,
the mechanical consequences of biodegradation can be troublesome
with long-term settlements ranging between 25% and 40% of
original waste height.       
However, the lack of a fundamental description of solid phase loss
and induced changes in void volume means that, in geomechanics at
least, analysis of these soil-like materials is constrained to a
highly empirical path.
This presentation seeks to elucidate a more fundamental mechanism of
decomposition-induced settlement. A relationship between void volume
changes and decomposition of the solid fraction, effectively a
constitutive relationship, is derived and described by a single
(scalar) parameter. Key patterns of volumetric response to
decomposition are highlighted. The decomposition-induced void change
parameter is shown to be capable of interpreting the sometimes
episodic process of volumetric strain in a decomposable soil-like
material.
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Kozreadta: Van Peter