A theoretical procedure estimating the thermal and hydraulic conductivities of jointed rock masses is presented. The method for appoximating the thermal expansion coefficients of well- jointed rock masses is also described. The proposed theory can handle arbitrary joint orientations and numbers of joints in two dimensions and three dimensions. Various joint geometries with different levels of complexity are tested through numerical experiments using the finite element method. Different types of boundary conditions are tested in the experiments. The equivalent thermal and hydraulic properties predicted by the theory are in good agreement with the experimental results over practical ranges of joint properties.


On presente une procedure theorique qui estime les conductivites thermiques et hydrauliques des masses rocheuses jointees. La methode pour approximer les coefficients de I'expansion thermique des masses rocheuses jointees est egalement decrite. La theorie proposee peut mainier les orientations de joint arbitraires et les nombre des joints dans deux et trois dimensions. Les geometries de joint diverses sont testees par experiences en utilisant la methode des elements finis. Les sortes differentes des conditions de la borne sont testees dans les experiences. Les proprietes thermiques et hydrauliques equivalentes prevus par la theorie correspondent bien aux resultats experimentaux sur la portee pratique des proprietes de joint.


Ein theoretisches Verfahren, das die thermischen und hydraulischen Leitfahigkeiten gekluefteter Gebirge ahschatzt, wird dargestellt. Die Methode, um die thermischen Ausdehnungskoeffizienten gut gekluefteter Gebirge anzunahern, wird auch beschrieben. Die vorge- Schlagene Theorie kann willkuerliche Kluftstellungen und Kluftanzahlen in zwei Dimensionen und drei Dimensionen handhaben. Mehrere Kluftgeometrien mit verschiedenen Verwicklungsniveaus Werden mittels numerischer Versuche, die die Methode der finiten Elemente benutzen, geprueft. Verschiedene Grenzbedingungstypen werden in den Versuchen geprueft. Die durch die Theorie vorau gesagten aquivalenten thermischen und hydraulischen Eigenschaften stimmen gut mit den experimentellen Ergebnissen fuer praktische Wertbereiche der Klufteigenschaften ueberein.


A Primary concern in rock mechanics design of underground structures in rock masses is the role of geologic features such as joints, faults, bedding planes in engineering scale, and fractures and cracks in the microscale. Mechanical properties of the rock masses depend on the geo- metrical and mechanical characteristics of the discontinuities that are present in the field but not in the laboratory test specimens. Gerrard (1982) has studied the elastic properties of rock masses having one, two and three sets of orthogonal joints. Moon (1987) suggested a scheme to estimate the elastic moduli of well-jointed rock masses having arbitrary joint orientations and numbers of joints in both two dimensions and three dimensions. The essential feature of the scheme is integrating in sequential manner the individual effects of joints into the equivalent (overall) elastic properties. The sequential method has virtually resolved the difficulties many geomechanics design engineers face in practice dealing with irregular joint patterns. The equivalent properties approach can also be found in composite mechanics theories, for example, the Hashin-Shtrikman bounds for multiphase materials and the self-consistent method for cracked solids (Hasin and Shtrikman, 1963; Budiansky and O'Connell, 1976). The basic concept usually employed in composite mechanics is the representative volume element (RVE) defined by Hill (1963). In the case of jointed rock mass, the RVE should include the typical joint structure so that the entire rock mass can be represented by a number of identical RVEs effectively. This is possible only if the joint geometry is periodic and regular as pointed out by Moon (1987). Unless the field tests on joints and joint-containing rock mass are possible on every scale of observation, the alternative is a theoretical approach which integrates all measurable pieces of information such as joint geometry, joint properties and intact rock properties.

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