Investigation of the mechanical behaviour of light and dense backfill material subjected to various pore fluid conditions

Sumi Siddiqua, James A. Blatz, Greg Siemens

In the proceedings of: GEO2011: 64th Canadian Geotechnical Conference, 14th Pan-American Conference on Soil Mechanics and Geotechnical Engineering, 5th Pan-American Conference on Teaching and Learning of Geotechnical Engineering

Session: Geoenvironmental Engineering

ABSTRACT: This paper summarizes triaxial and 1D-consolidation oedometer tests performed on light and dense backfill under a series of pore fluid chemistry. The pore fluids are distilled water, NaCl and CaCl2 solutions with a maximum total dissolved solids (TDS) of 250 g/L. Results of the tests are analyzed to evaluate the mechanical behaviour of the materials. The influence of pore fluid chemistry on the stress-strain behaviour is studied. Both triaxial and oedometer tests results are compared between two materials. Results are also presented for the specific volume with respect to mean effective stress for distilled water and saline solution tests condition. The light backfill which is composed of 50% sand and 50% bentonite clay by weight shows a noticeable sensitivity to the pore fluid chemistry on its mechanical properties. While dense backfill which is composed of 5% bentonite, 25% glacial lake clay and 70% crushed granite aggregate are not sensitive to the chemistry of the pore fluid.

RÉSUMÉ: Ce document résume les essais oedométriques triaxial et 1D-consolidation effectuée sur le remblai léger et dense, sous une série de la chimie des fluides des pores. Les fluides interstitiels sont l'eau distillée, de NaCl et CaCl2 solutions avec un maximum total des solides dissous (TDS) de 250 g / L. Les résultats des tests sont analysés pour évaluer le comportement mécanique des matériaux. L'influence de la chimie des fluides des pores sur le comportement de déformation des essais oedométriques et le comportement contrainte-déformation des essais triaxiaux sont étudiés. Les deux essais triaxiaux et oedométriques résultats sont comparés entre les deux matériaux. Les résultats sont également présentés pour le volume spécifique à l'égard de la contrainte effective moyenne pour l'eau distillée et de solution saline tests de condition. Le remblai léger qui se compose de 50% de sable et d'argile bentonite 50% en poids montre une sensibilité notable à la chimie du fluide interstitiel sur ses propriétés mécaniques. Bien que le remblayage dense qui se compose de 5% de bentonite, argile 25% du lac glaciaire et 70% agrégats de granit concassé ne sont pas sensibles à la chimie du fluide interstitiel.

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Cite this article:
Sumi Siddiqua; James A. Blatz; Greg Siemens (2011) Investigation of the mechanical behaviour of light and dense backfill material subjected to various pore fluid conditions in GEO2011. Ottawa, Ontario: Canadian Geotechnical Society.

@article{GEO11Paper236,author = Sumi Siddiqua; James A. Blatz; Greg Siemens ,title = Investigation of the mechanical behaviour of light and dense backfill material subjected to various pore fluid conditions,year = 2011}