Comparison of Direct and Indirect Assessments of Temperature Effects on Interface Shear Strength between Sand and HDPE Geomembranes

Tanay Karademir, David Frost

Dans les comptes rendus d’articles de la conférence: 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: The shear strength of granular soil-geomembrane interfaces is controlled by the mechanisms of friction including sliding, rolling and plowing acting during shearing which in turn, depend primarily on the relative hardness of the counterface materials and the angularity of the soil particles. The interfaces between sands and geomembranes in landfill applications are subject to elevated temperatures due to exothermic reactions occurring in the waste body. An experimental research study was undertaken to investigate temperature effects on the mobilized interface shear strength between sands and geomembranes. The laboratory testing program consisted of direct interface shear tests at temperatures ranging from 21°C up to 50°C. For this purpose, a temperature controlled chamber (TCC) was developed to evaluate shear displacementfailure mechanisms at elevated temperatures. Moreover, complementary surface hardness measurements on geomembrane samples were performed at various temperatures and then correlated to the change in temperature. A general relationship for interface frictional strength as a function of temperature was developed using a new empirical relationship developed between temperature and surface hardness and the relationship between hardness and normalized interface friction proposed earlier by others. Predictions made with this new empirical relationship were compared with direct measurements of the mobilized frictional shear strengths at elevated temperatures using an interface shear device enclosed by the TCC.

RÉSUMÉ: Cet article présente les résultats des essais de cisaillement direct effectués sur des interfaces de sable et de géomembrane à différentes températures allant de 21 ° C à 50 ° C dans la chambre à température contrôlée. Des mesures complémentaires dureté de surface sur des échantillons de géomembrane ont été effectuées à différentes températures élevées pour établir des corrélations empiriques pour évaluer indirectement les effets de température sur la résistance au cisaillement d'interface entre le sable et géomembrane PEHD, ainsi que de comparer avec les données expérimentales acquises grâce à des mesures en laboratoire direct (à savoir: l'interface de cisaillement tests) à des températures élevées.

Please include this code when submitting a data update: GEO2011_120

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