A constitutive law for thermo-plastic behaviour of rocks: an analogy with clays

TitleA constitutive law for thermo-plastic behaviour of rocks: an analogy with clays
Publication TypeJournal Article
Year of Publication1994
AuthorsT Hueckel, A Peano, and R Pellegrini
JournalSurveys in Geophysics
Volume15
Start Page643
Issue5
Pagination643 - 671
Date Published09/1994
Abstract

Thermo-mechanical behaviour of rocks shows phenomenological similarities to that of clays. A visible decrease of strength and an increase in ductility at elevated temperatures are observed in drained conditions. In undrained conditions the strength decrease is even more dramatic and the ductile behaviour may turn into the brittle one, if a sufficient amount of water is present in the pores at the start of the process, or it is being released during heating by the decomposition of hydrous minerals. Applying a thermo-plasticity theory, major macroscopical characteristics of behaviour may be modelled. According to this theory, the elastic domain is postulated as temperature dependent, shrinking with temperature; heating may result in expansive or compactive volumetric irreversible strain depending on the confining stress. This theory is applied to the modelling of heat effects on local changes of permeability around a cylindrical nuclear waste container disposed off in deep clays, and in the numerical simulation of a mechanism initiating deep earthquakes. © 1994 Kluwer Academic Publishers.

DOI10.1007/BF00690178
Short TitleSurveys in Geophysics