One of the ways of preparing frozen rocks for excavation is thawing. However, the use of traditional heating methods for this purpose can not be recognized as satisfactory, both because of the low rate of thawing due to the low thermal conductivity of frozen rocks, and because of the negative effect of heating sources on the thermal regime of excavation.

The most characteristic feature of frozen rock mining is its high energy intensity and cost. Ice cemented loose rocks at low subzero temperatures become so strong that their excavation without preliminary preparation turns out to be ineffective. ...

An interuniversity educational and methodological conference of the teaching staff on the problems of improving higher mining education was held at the Leningrad Mining Institute. The conference was attended by representatives of 18 mining and metallurgical universities and mining faculties of polytechnic institutes of the country.

It is well known that there is no single measurement method for determining the modulus and phase of the complex transmission coefficient of quadrupoles in the range of high and ultrahigh frequencies. For definition of these quantities in the specified range of frequencies it is necessary to use a number of measuring devices working on different principles and providing not equal accuracy of measurements. This reduces the value of measurement results and the possibility of their use, for example, to determine the dielectric constants of materials.

The behavior of an antenna in a borehole in terms of its input impedance is of interest in connection with the investigation of the possibility of extending boreholes in frozen rocks to large diameters using microwave energy.

The electrode system and the heated frozen rock form a so-called working capacitor, whose characteristics are electrical capacitance and tgδ (loss angle). Knowing these characteristics, it is possible to determine all elements of the high-frequency circuit that forms the energy source of the technological process...

The rocks of the oil shale formation of the Baltic basin, of which the Estonian deposit is a part, are characterized by three features that complicate both the determination of physical and mechanical properties of rocks and the study of the process of destruction of the massif by the action of explosion: 1) oil shale is not an isotropic body, but a finely layered medium; 2) the high clay content and porosity of both oil shale and some limestone interlayers make them highly plastic; 3) the presence of moisture and limestone inclusions in oil shale layers makes oil shale be considered as a multicomponent medium. ..

Further realization of grandiose tasks of peaceful development of the USSR national economy requires even wider use of explosives energy in the development of mineral deposits in the field of industrial, railway and hydraulic engineering construction and in other sectors of the economy. Meanwhile, the issue of determining the size of explosive charges is still not developed sufficiently, and existing methods of calculation often give incorrect results.

Manual labor in the production of exploration and engineering-geological research still occupies a large place. Among these works, manual drilling of boreholes in the exploration workings is of no small importance. Labor productivity in manual drilling is low. For example, for sinking a borehole depth of 1.5 meters and a diameter of 35 mm in rocks of medium strength is spent 3.14 man-hours. The use of existing mechanisms for borehole drilling in exploratory excavations in some cases is impossible due to the lack of energy sources. Large volume, labor intensity and high cost of manual drilling urgently require mechanization of this process.