American Society of Civil Engineers


Reactive Transport in Cut-Off Walls and Implications for Wall Durability


by Stephan A. Jefferis, (Director, Environmental Geotechnics Ltd, Talbot Lodge, Middleton Stoney, OXON, OX25 4AD, England and Visiting Professor, University of Oxford E-mail: egl@environmentalgeotechnics.com)
Section: Reactive and Hydraulic Vertical Barriers, pp. 652-659, (doi:  http://dx.doi.org/10.1061/40970(309)82)

     Access full text
     Purchase Subscription
     Permissions for Reuse  

Document type: Conference Proceeding Paper
Part of: GeoCongress 2008: Geotechnics of Waste Management and Remediation
Abstract: Permeability is a key parameter for any containment system including cut-off walls but it tends to be regarded as a fixed property such as strength, sensitive principally to changes in the effective stress or chemical damage. Furthermore chemical attack, if it occurs, tends to be treated as a ‘one-off’ phenomenon. However, a barrier material such as a cement-bentonite is actually chemically reactive system with a dynamic permeability. Flow through this reactor is controlled by the overall permeability of all the reaction zones that develop within it. High permeability reactive barriers (PRBs) are well recognized for the management of contaminated groundwater but low permeability barriers are less often considered as reactors and opportunities for barrier protection and maintenance therefore can be overlooked. This paper is focused on the permeation of water through cement-bentonite materials: much can be learned from this about the dynamic permeability of the reactive matrix that a cement-bentonite material represents.


ASCE Subject Headings:
Walls
Durability
Parameters
Trenches