ABSTRACT:

Due to the mechanism of rock burst realisation taking place on account of different disturbances suggested is a dynamical model of a rock burst. The suggested model is based on the main principles of analytical mechanics. To formalize the process of rock burst preparation and its realisation used are linear and non-linear Lagrange dynamic equations.

RESUME:

Sortaut du mecanisme de la realisation des coups de toit crees des perturbations dynamiques on propose un modele dynamique du coup de toit. Ce modele propose base aux principes fondamebtals de la mecanique rationelle. Pour description de l'evolution et de realisation des coups de toit on utilise des equations lineaires et non-lineaires de la dynamique en forme de Lagrange.

ZUSAMMENFASSUNG:

Es ist das dynamische Modell des Gebirgsschlages vorgeschlagen, das aus dem Mechanismus der Realisierung von Geblrgsschlagen als Störungen unterschledlicher physikalischer Natur hervorgeht. Diesem Modell liegen die Hauptprinzipien der analytischen Mechanik zugrunde. Zum Formalisieren des Prozesses der Vorbereitung und der Realisierung von Gebirgsschlagen werden lineare und inlineare dynamische Lagrangesche Gleichungen verwendet.

INTRODUCTION:

The rock-burst prediction and rock-pressure control are based on use of deformation process Laws, which finally leads to rock destruction. The well known hypotheses of rock burst formation are qualitative ones, which is revealed in unsatisfactory rock burst prediction. The methods of elastic theory and linear mechanics of destruction which are widely and successfully used in geomechanics could rather well localise the massif parts where there are the enhanced strain regions. However, the theories could not determine the level when the strains and deformation would be unfinite. The aim of the work is to use the dynamics equations for investigation of the preparation and realization of rock-burst phenomena.

1. The mechanism of transition from macro to microdestruction. The experimental study of rock destruction shows that elementary destruction act -s the appearance of micro cracks, whose sizes are determined by the material peculiarities. The micro cracks formed are restricted by the boundaries of structure elements. In the vicinity of the microcrack the reconstruction and redistribution of the stain take place. Due to this fact, the prelinary destruction stages are rather long because microcrack accumulation takes place up to its certain concentration. The qualitatively kinetic theory [1–2) considers this process on the basis of statistic laws. But the theory doesn't consider the massif movement. The massif, however, should move. It demonstrates long period elastic oscillations caused by the Earths own oscillations. Besides, the massif is affected by different impulsive influences (explosions and earthquakes). Moreover, one should take into consideration the unlinearity of medium and unpossibility to use the Hook law when deformation develops. Hence, a massif is a physically non-linear medium in which the Kinetic process of crack formation is being eventually developed due to inner stresses and outer force influences. The Kinetic process takes place when the accumulation of cracks from micro to macro level is observed. During the process there observed the elastic oscillations of a wide spectra frequencies. On account of interferention and dispersion of the elastic waves the generation limits of elastic (potential) energy density could be reached, which transforms the system to absolutely instable one on the stage of preparation to rockburst. At this stage the process of crack development becomes an explosive one and massif deformations together with displacements are unrestricted. Such unlinear effects are discribed by Bussinesk equation which looks like a wave one and has the decision in a form of stationary waves with the conservation of a wave profile. It is well known that unlinear equations have not such a property.

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