A laboratory physical model to analyse flow and transport processes in a fractured rock sample at bench scale level

Cherubini, Claudia, Giasi, Concetta and Pastore, Nicola (2013) A laboratory physical model to analyse flow and transport processes in a fractured rock sample at bench scale level. Italian Journal of Engineering Geology and Environment, 2013 1: 19-32. doi:10.4408/IJEGE.2013-01.O-02

Author Cherubini, Claudia
Giasi, Concetta
Pastore, Nicola
Title A laboratory physical model to analyse flow and transport processes in a fractured rock sample at bench scale level
Journal name Italian Journal of Engineering Geology and Environment
ISSN 1825-6635
Publication date 2013-01-01
Sub-type Article (original research)
DOI 10.4408/IJEGE.2013-01.O-02
Open Access Status DOI
Volume 2013
Issue 1
Start page 19
End page 32
Total pages 14
Place of publication Rome, Italy
Publisher Sapienza Universita Editrice
Language eng
Abstract The knowledge of flow and transport phenomena in fractured rocks is very important in hydrogeologic engineering in order to optimize clean up and monitoring strategies, to carry out risk assessment and to manage interventions in aquifers. Recently, understanding, characterizing and modeling physical and chemical interactions within fractured aquifers has acquired increasing importance, especially with regard to the question of water resources development and groundwater contamination. Sometimes the equivalent porous medium approach fails to reproduce flow and transport patterns in such complex geological formations. Critical emerging issues for fractured aquifers are the validity of the Darcian-type "local cubic law" which assumes a linear relationship between flow rate and pressure gradient to accurately describe flow patterns and of the classical advection-dispersion equation to describe the propagation of solute. Most studies of transport through discrete fractures are still based on simpler flow models which has limited the interpretation of solute breakthrough curves. Experimental data obtained under controlled conditions such as in a laboratory allow to increase the understanding of the fundamental physics of fluid flow and solute transport in fractures. In this study hydraulic and tracer tests on artificially created fractured rock samples of parallelepiped (0.60×0.40×0.8m) shape have been carried out. The volumes of water passing through different paths across the fractured sample for various hydraulic head differences and breakthrough curves for saline tracer pulse across different pathways have been measured. The above experiments are aimed at understanding the relations existing between the applied boundary conditions, the geometry of the system and the occurring flow and transport phenomena. The experimental results have shown evidence of non linearity in flow and concentration profiles that cannot be described by conventional solute transport models. In fact, the classical advection-dispersion equation -used as a benchmark for comparison in a numerical model- poorly describes the experimental breakthrough curves of the tracer propagation. A comparative analysis of the obtained results has allowed to study the behavior of flow and transport in the investigated medium on the one hand, and to evaluate possible improvements to the experimental setup on the other.
Keyword Fractured media
Laboratory experiments
Non-darcian flow
Non-fickian transport
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status Non-UQ

Document type: Journal Article
Sub-type: Article (original research)
Collection: School of Civil Engineering Publications
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Created: Tue, 08 Sep 2015, 07:41:25 EST by Jeannette Watson on behalf of School of Civil Engineering