ABSTRACT:

The elements of the new theory of quantitative definition of fracturing, the estimation of structural hierarchy of rock massifs based on the spectral and correlation analysis of data of electrometric and nuclear-geophysical logging are set forth. The new method of the borehole electrometric diagnostics of the form of stressed-strained state (SSS) of rocks is described. The new geomechanical effects revealed by means of the geophysical measurements in the mines of the Talnakhsko- Oktyabrsky deposit (USSR): the effect of the sign-variable reaction of massifs on the dynamic actions and the phenomenon of the zonal disintegration of rocks around the underground minings are described.

1 INTRODUCTION

The knowledge about the stressed strained state and the geomechanical processes in rock massifs has the basic importance as for the safety of carrying out of mining work, as in terms of improving of technological solutions. At present the geophysical express-methods such as seismic, seismoacoustic, electrometric, radiometric and others gained wide application for the solution of geomechanical problems. The borehole geophysical methods such as electrometry and radiometry, which are used for the solution of geomechanical problems received a development in the Institute of Mining. And as this took place, much attention was given to the development of the foundations of the theory of the geomechanical interpretation of data of geophysical logging, including the most important component parts such as the borehole geophysical fracture detection and diagnostics of the of the stressed strained state (SSS) of rock massifs. The main role in the theoretical in vestigations belongs to the results of measurement in situ in the mines of Norilsk complex deposit, where the mining works approach to the depth-1500 m. For more wide verification of the most important positions, the results of the investigations, the results of the investigations carried out by us in the Sheregeshsky Mine, which is among the enterprise "Sibruda", are used with the data of other scientists.

2 THE BOREHOLE GEOPHYSICAL FRACTURE DETECTION

Usually the visual observations on the surfaces of openings or the analysis of the yield of core when the hole is drilling with allowance for intensity of the secondary changes are used in the mining practice for evaluation of rock disruption. Depending on the method, which is used for estimation of fracturing of rocks, it is suggested a number of fracturing coefficients. However, the direct application of these parameters for determination of state of rock massifs in the light of predicting of their behavior under the influence of winning entails difficulties of principle character as the obtainment of the above mentioned indices is often connected with subjective factors. For scientific well-grounded conclusions concerning the character of changes taking place in the massif, which are shown specifically because of the processes of discompaction, forming fracture, etc., it is necessary to use such indices, the obtainment of which is free from subjective factor. We consider a new point of view on the study of structural features of rock massif and their changes, which occur in the result of technological actions.

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