The authors of the paper have developed a method and equipment for monitoring stress variations in the ground in order to forecast seismic Phenomena. The basis of the recording consists of the formation or a measuring slot in the rock into which sensitive element, i.e. a stress sensor, is installed. During tests which were carried out in an Operational mine alterations of stresses as a result of mining work were ascertained. Stress monitoring measurements that were taken in the vicinity of the dam at the Ingouri underground hydro-electric power station during construction indicated alterations in the form of a "bay". The alterations are identical to those that preceded the failure of the laboratory samples.
Die Autoren dieser Arbeit haben eine Methodik und eine Apparatur ausgearbeitet fuer die Kontrolle der Spannungsvariationen in Erdboden, welche fuer die Prognose der seismischen Erscheinungen bestimmt sind. Das Registrier Prinzip besteht in der Fertigung einer Mess-Spalte im Erdgestein, in die ein empfindliches Element, namlich ein Spannungsgeber hineingestellt wird. wahrend der Versuche,die in einem im Betrieb befindlichen Bergwerk durchgefuehrt wurden, wurden Spannungsanderungen infolge der Bergwerksarbeiten festgestellt. Die spannungskontrollmessungen, die im Bereich des im Bau befindllchen Dammes, des in den Bergen gelegenen Wasserkraftwerkes Ingouri, durchgefuehrt werden zeigten Veranderungen in Form einer 'Bucht'. Diese An- derungen sind identisch mit denen, die dem Bruch der Laborproben vorangingen.
Les auteurs de cette etude out elabore une methode theorique et experimentale de l''euregistrement des variations de tensions dans Ie massif de roches. Le complexe d''enregistrement se compose des elements tensometrique et compensateur. La sensibilite de la methode est determinee par le coefficient de transformation entre Ie transfigurateur de deformations et la membrane de l''enregistreur. Pendant les essais realises dans une mimere fonctionnante ońt ete en- registrees les variations de tensions provoquees par facteurs tectoniques. Les essais de contrôle de tensions effectues dans la zone de construction de la digue de la station hydroelectrique à Ingouri, situee dans les montagneS, ont enregistres des variations du type "de baie". Ces variations sont identiques aux variations precedantes la destruction des speecimes au laboratoire.
The analysis of existing methods and means of seismic phenomena forecashing show that/hitherto there are no reliable solutions of the earthquake and seismic shock problem. The forecashing of the mentioned phenomena is based on obtaining and analysing the data that indirectly define the Earth8s stresses. It may be supposed that recording of stressed and deformed state variations will allow to improve the prognostic investigations. The heterogeneity and discretness of mechanical rock properties on different scale levals /1,2/require a simataneous observation of the stress variations in many points.
The available results of earthquake precursor observations testify to anomalous deformation variations from 10−7to 10−8/3,4/. Such a sensitivity must be also inherent to the apparatus for stress variation recording. In addition, the apparatus being developed must be cheap, simple in building and operating.
The authors of the present work have developed techniques and devices for Earth''s stress variations control with the object of forecashing the seismic phenomena. The registration principle consists in formation of a measuring slot in the rock with a consequent installing into it of a sensitive element, i.e. of a stress sensor.
1.1Control techniques and apparatus Let the large edges of the measuring slot be normal to the controlled component of the external stress tensor. The rock around slot considered to be elastic and ropic, its temperature being invariable.
