The diversity factors and types of stresses occurring in drilling diamonds crucial thermal and mechanical stresses on stress-deformation condition and, ultimately, the efficiency of diamond tools. Showing ways to improve designs and ways to prevent their crowns abnormal wear.

In the article questions of development of mathematical-mechanical model of rock destruction process, abnormal wearout of diamond bits, mechanical and temperature tensions in drill diamonds, technology of drilling with new diamond bits were observed.

It is considered the mechanism of formation of cracks of the round closed outline at action on breed of an individual chisel cutter. Pressure hinks arising on a face are investigated. Recommendations about designing of chisel crowns are made.

Geodynamical variability is a cause of different natural disasters, such as earthquakes, volcanic eruptions, earthflows and seismic sea spillages. Natural disasters can activate technogenic catastrophes (building and construction failures, coal-mine explosions, dam integrity disturbance etc.). Technogenic catastrophes, in their turn, are able to originate such natural disasters as dam lake occurrence; the Earth crust’s surges with hazard consequences can be provoked by oil and gas extraction performance.Examples of natural disasters and technogenic catastrophes, factors of their origin, the phenomena prediction and avoidance recommendations have been shared in the following article.

Studies conducted in the mines «Rostovugol», showed that, for assessing the sustainability of preparatory excavations in the management of sewage treatment works is enough to determine the allowable values of convergence of the roof and ground-level workings and potential energy of elastic deformation of the pillars. These indicators can be used in the coal mines of other basins.

Construction and operation of ductless heating networks in St. Petersburg is characterized by a number of difficulties associated with a high degree of watered soil and, in particular, with the presence of buried peat bogs. Microorganisms of these peat bogs contribute to the development of corrosion processes in steel pipes of heating networks. The article gives recommendations on prevention of pipe corrosion during operation of heating mains in such conditions.

Saint Petersburg Mining Institute for the entire period of its existence (more than 230 years) has gained fame as a center for the development of culture and social relations in Russia. The article below is devoted to the contribution of the Mining Institute to the social and cultural life of the country, the role of students of the Institute, one of the largest scientific and educational institutions of global importance, in the development of Russian philosophical science, literature, and Russian civil society

Stability of viscoplastic rocks (clays, salts, ice) in the walls of deep wells can be evaluated based on the theory of aging (steady-state creep), for which we propose a proven in practice methodology for determining the stresses on the contour of the wellbore section, radial displacements of points on this contour and their speed.

The mass valuation of real estate does not allow taking into account individual features of buildings that can have a significant impact on the value of the object. In this case certain difficulties arise in the calculation of functional depreciation. The method of operative definition of functional depreciation of real estate with the use of compilations of consolidated indicators of restoration value is suggested.

The study of energy balance in rock fracture is one of the directions of the scientific school of deformable solid mechanics developed for several decades at the Department of Structural Mechanics of the St. Petersburg (Leningrad) Mining Institute. The formation of this school is connected with the works of L.S. Burshtein, N.S. Bulychev, N.N. Kaidalov, A.N. Stavrogin and others. The practical results of this school are known at many sites of underground construction, in the mining industry, in exploratory drilling. Within the framework of this article, modern ideas about the mechanism of transformation of potential energy of elastic compression into dynamic types of energy during brittle fracture are briefly described, the balance of energy of this process is given, as well as examples of its use in solving a number of contact problems of exploratory drilling, least covered in the technical literature.

The stability of the clay outcrop when driving transport or sewage tunnels determines the efficiency and safety of mining operations, as the time of the steady state of the clay outcrop depends on the regulated lag of the permanent excavation support, the mechanization method of excavation works, the time of rock mass removal, etc. In addition, clayey strata in recent years are widely used as storage facilities for various wastes (e.g., radioactive), so the steady state time of the outcrop plays an important role here, too.

Widespread introduction of SSC complexes into the practice of drilling operations allowed to significantly reduce non-productive time spent on downhole operations.

In the design of diamond rock-cutting tools, of considerable interest is the evaluation of their stress-strain state during drilling, or dynamic interaction with the rock mass.

It is known from the practice of drilling wells (both exploratory and special purpose) during mining and construction works that a significant proportion of well accidents is caused by drill pipe string breaks.

The efficiency of diamond drilling tools is determined by the mass of bulk diamonds embedded in them. Deviation from the optimum in one or another direction leads to a decrease in drilling performance.

Specific properties of foams is their low density, low erosive effect on the walls of the well, increased in comparison with water carrying capacity, etc. ...

At geological exploration drilling for elimination of all kinds of complications is spent up to 25% of the calendar time of work of drilling rigs, and drilling productivity in some cases is halved ...

Prediction of the mechanical drilling speed as one of the potential capabilities of diamond rock-destroying tools, conditioned by the design features of the tool, characteristics of the cleaning agent, drillable rocks and drilling technology, is the basis for the application of methods of optimization of diamond drilling processes ...

It is known that the mode of cleaning the rock-drilling tool from cuttings largely determines the efficiency of the diamond drilling process. However, until now there are practically no objective criteria for determining the optimal flow rate of cleaning agent, providing both the required degree of cleaning of diamond tools from cuttings and proper cooling during the process of rock destruction during drilling ...

Successes in the synthesis of new superhard materials, in particular, cubic boron nitride (elboron), which has increased heat resistance compared to natural diamond and hard alloy (respectively 1.8 and 1.6 times) and chemical inertness to ferrous compounds, opened wide opportunities to expand and improve the raw material base for the manufacture of drilling rock-destroying tools ...

Significant expansion of diamond drilling has put forward a new area of research related to the study of the nature of diamond drill bits in conditions of high contact temperatures, which are characterized by the destruction of the hardest rocks and drilling with compressed air blowing ...

Exploration of the Tyrnyauz deposit, carried out on the flanks mainly by means of mining and drilling operations, is complicated not only by specific features of the highlands, but mainly by thick (from 50 to 180 m) deluvial-moraine deposits. These sediments are represented by unconnected fragments of altered rocks of different hardness and abrasiveness: mudstones, siltstones, tuff-sandstones, granite-gneisses and hornblende of various compositions. In addition, on the northern slopes of the ridge there are widespread areas of permafrost, which makes the specifics of drilling operations close to the conditions of the Far North.

Standard tungsten-cobalt carbide bonds, depending on their hardness and purpose, are produced by cold (No. 3, 20-25 HRC, and No. 4, 30-35 HRC) and hot (No. 5, 50-55 HRC) pressing methods. Temperatures of sintering of bond-matrixes vary in the range from 1150 (No. 3) to 1350°C (No. 5) and in a reducing medium do not lead to the appearance of noticeable traces of graphitization. or loss of mechanical strength in perfect single crystals of natural diamond.

“The area of the Deputatskoye field, where drilling was carried out, is composed of lithologically monotonous sediment strata dislocated in large gentle folds of sublatitudinal and northeastern strike. In terms of physical and mechanical properties that determine the choice of diamond tools, the rocks composing the deposit can be divided into three main groups: 1) heavily crushed, often crushed medium- and fine-grained sandstones and sandy-clay shales cemented with calcareous material and ice, VІІІІ-ІХ categories of drillability; 2) sandy-clay shales of VІІІІ category of drillability; 3) dense occluded, in some places keratinized fine-grained low-abrasive sandstones of X-XІ categories of drillability.

Due to the special sensitivity of diamonds to the temperature factor, compliance with the normal thermal regime of diamond bits during drilling is one of the main conditions for their efficient operation. The normal thermal regime should be considered to be such a thermal regime at which the diamond heating temperature does not reach the value causing their oxidation, graphitization or deformation due to temperature stresses.