For rock behaviour and rock genesis the energetic surrounding may be of first importance; the energy-content characterizing strength and durability is in close dependency on it. The paper deals with the energetic conditions of the rock-forming elements, following an established petrophysical rock model and with the energetic evolution of each genetic rock family.
L'entourage energetique est de premiere importance pour le comportement et le genèse des roches; la teneur en energie, caracterisant la resistance mecanique et la durabilite des roches suive ses changements. Le rapport s'occupe des conditions energetiques des elements, composants des roches, selon un modèle petrophysique, specialement construit et de l'evolution energetique des familles genetiques de petrographie.
The properties of rocks, as heterogeneous and following the sophisticated rules of petrology compound bodies depend in a hierarchic manner on properties and changes of different rock-forming elements. Analysis of these rock-forming elements has been often effectueted in the applied petrophysics and rock mechanics, but the interdepences were generally not deeply treated. Therefore for an overview and interpretation of the correlations, the rock-forming elements have been summarized in a so called rock model (Galos-Kertesz, 1983., Galos et al. 1988.) It is to establish from this rock model (Table 1.) that the rock forming elements are from different sizes and they may be both, spatial and superficial. We can state too, that the behaviour of each spatial model-element is composed from the behaviour of a spatial model-element of smaller size and of a -- often negligible -- superficial element. This rock model gives the basis of the further discussion and is appropriate for a correct overview of be behaviour, as well as of the genetic and changing conditions of rocks. Rocks are formed through geologic processes, they change later through natural and artificial processes: for all these processes the thermodynamic laws are effective (too), whose most important characteristic is the strive for equilibrium. The equilibrium means in this case also the homogeneous distribution of the intensive thermodynamic quantities (f.i. energy-density) in the examined system (e.g. in spatial element of the Earth's crust). The processes are in the same way processes of energy- -equalization. The direction of the natural geologic processes is determined by the direction of the diminution of the inhomogeneity. The so observable interaction is a geologic one in the manner, that the succeeding (e.g. structural, crystallographical) physical states are one after the other more probable (perfect) than the previous one, until as long as the equilibrium is not established or the energy-conditions are not disturbed through a new energy-source. These processes are generally spontaneously carried out until obtaining the entropy-maximum, in some cases instable states may also conserved with an only local maximum in entropy; the spontaneous process is this way interrupted and may be only continued after an activation. All geologic matters -- f.i. minerals, rocks -- are situated in an intermediate or final (equilibrium) state, the artificial effects may be superimposed on them, therefore it seems to be opportune to discuss their energy-conditions.
The properties of the continuous rock blocks are determined by the elements of the rock model, that means by the rock-forming consituents and the joints between them; in the discontinuous rock bodies the elements of the discontinuity-system may playa technically important role too. Among this, less clear and accepted in the science are characteristics and role of the joints (bonds). Fracture mechanics deals detailed with fissures and discontinuities, but less usual is the analysis of the energy-reducing effect of discontinuity-systems in rock masses.
