The purpose of study is to clarify the specifics of the formation of kimberlite-controlling faults in Malo-Botuobinsky region, Yakutian diamond-bearing province, using physical modeling of rupture genesis for the sedimentary cover with alternating movements of the foundation blocks. Physical modeling for equivalent materials has been carried out at the Tectonic Physics Laboratory of the Earth's Crust Institute. As the model material, an aqueous suspension of montmorillonite clay with viscosity of 10⁶-10⁷ Pa·s has been used. For the purpose of the experiment, a special setup “Basement 3” has been made. The setup consists of a series of linearly elongated blocks imitating the fault-block structure of the Vilyui-Markhinsk fault zone of the Siberian platform within the study area. In the series of 12 experiments, the effect of the experimental setup dies’ velocity and displacement vector on the specific structural paragenesis of the secondary faults formed in the model platform cover has been studied. The comparison of the fault networks obtained in experiments with different boundary conditions, and the fault-block structure scheme of the Mirny kimberlite field and the kimberlitic bodies plans has clarified the specifics of the kimberlitic-controlling faults formation in the study area. The conclusion is that the fault network within the area of dynamic influence of the Vilyui-Markha faults has been formed at a relatively low rate of the platform basement blocks displacement. This is confirmed by the fact that the fault network with the parameters comparable with the natural model is observed at a low speed of the experimental setup dies displacement. The extension structures that are most favorable for ore deposition are observed in the models with a slow rate of the experimental setup dies displacement. Besides, they are formed in the fault zones with alternating block displacements only at the second stage of model deformation (after changing the direction of the basement blocks movement) in strike-slip or transtension conditions. In the second-stage transtension conditions, openings of this type are not observed; and under transpression, the tension is observed not only for the e -type openings, but also for the cleavage planes of the second stage model deformation. The highest amplitude tension structures of all types tend to belong to the central parts of the model fault zones.

In view of the difficult situation in the country in recent years regarding the accumulated environmental damage, including that caused by arsenic-containing waste of mining and processing industry, there is an urgent need to develop a methodology to eliminate the social and environmental consequences of this negative impact. The article presents a study of the soil sorption properties for the Svirsk municipal district that has been long subject to the arsenic waste pollution. In the course of the experiments, the sorption capacity of various soils typical of the examined territory has been defined. The study has shown that among the studied soil types, the dense scaly brownish loamy soils are distinguished as having the highest sorption capacity. The soil with the capacity of 2 to 9 m has proved to be an important geo-ecological barrier prohibiting penetration of arsenic and heavy metals into the underlying aquifers. Using the obtained data, a computer model has been developed with the purpose to predict the arsenic spread in the soil. Based on the research results, the remediation technology for the Svirsk municipal district has been developed. Using the data on various soil types’ sorption capacity and the layer thickness, it is possible to identify the territory zones that have the highest potential for self-conservation i.e. immobilization of mobile arsenic forms in the natural geochemical barrier. The developed model of arsenic migration can be used for predicting the toxicant spread in other regions contaminated with arsenic-containing waste of mining and processing industries.

The main electrical prospecting technique in the study of the geological section of the Siberian platform sedimentary cover is a near-field transient electromagnetic method (TEM) used for oil and gas exploration along with seismic prospecting. In recent years more and more signals complicated by the effect of induction-induced polarization (IIP) are registered. Interpretation of such signals in the horizontally stratified conductive models leads to errors when defining the resistivity of the sedimentary cover horizons located in the target interval of the section. The aim of the study has been to define the IIP-complicated transient response registered during the areal exploration for oil and gas, as well as to develop guidelines for interpreting the TEM data with the account of the induced polarization (IP). Using mathematical modeling, the IP effect has been evaluated for the transient characteristics calculated by the model in which the polarized horizon is located at different depths. Based on the TEM data inversion results considering the IP, the effectiveness of methodology has been validated. According to the inversion results, the IP manifestation is associated with the rocks in the upper part of the section. The nature of IP is explained by the presence of pyrite in the Jurassic and Upper Cambrian sediments. The resistivity distribution for the target horizons with the account of IP is lognormal. Applying the parameter characterizing the TEM curve divergence at the qualitative analysis stage allows the area zoning by the degree of IIP manifestation. Interpretation of the TEM data with the account of IP enhances the accuracy of the TEM data inversion and allows to obtain the models that are consistent with the geological structure of the survey area. Thus, it enables a detailed forecast of the reservoir properties of the subsalt sediments.

The article considers advanced approaches to interpreting electromagnetic data i.e. near-field transient electromagnetic sounding (TEM) that provide prompt information on the area under study. The electric facies analysis is an innovative technique of electromagnetic survey in which at the stage of the qualitative analysis of the electromagnetic survey data, the initial curves are integrated into the GeoDepth Paradigm seismic processing package by means of specialized software. As a result of the study, electric facies for the main geoelectric complexes have been mapped in the Stratimagic environment. The maps are based on the stratigraphic marks obtained by the seismic survey. The comparison of the electric facies maps and longitudinal conductivity maps shows the anomalous field match which confirms the method correctness. The electric facies classes are thereafter compared with the test data on the deep-hole wells located in the studied area. The electric facies analysis significantly increases the level and enhanced the informational content of the qualitative analysis of the TEM data. The integration of the electromagnetic data in seismic software packages facilitates integration at all stages of the geophysical data interpretation, thus increasing the validity of the complex predictive parameter and the reliability of mapping for the promising oil-and-gas sites.

The purpose of the study has been to investigate the character of distortion of the reflected signals from different semispaces using the reflection separation procedure. The knowledge of the distortion character and influencing parameters makes it possible to select an effective method of field works and processing. The article presents the underground seismic survey results obtained using the reflected wave method, i.e. common depth point procedure. In the frames of the method, with the participation of the author, an underground seismics method using shear waves with reflection separation has been developed and tested at the Verkhnekamskoye potash salt deposit. With the reflection separation, the signal distortion depends mainly on the distance between the source points lines. Following the direct task of seismic survey, the signals have been modeled for different distances between the reception lines. The study has shown clear regularities in the effect of the distance between the source point lines on the characteristics of the separated reflected signals. The quality of the signal suppression virtually independent on the distance between the source points lines. For an enhanced signal, it is the opposite: depending on the distance between the source point lines, both the signal amplitude and phase get distorted. The signal length also changes: when enhancing the signal coming from below, the elongation happens in the direction of the record beginning, and for a signal coming from above, in the direction of the record end, the quality of signal suppression being almost in no dependence to anything. Vice versa, an enhanced signal is subject to any kind of distortion when the distance between the source point lines changes. Based on the research results, it is possible to choose a distance that provides optimum reflection separation corresponding to a research task.

Walking excavators (ESH) are the main mechanization means when developing coal fields in the regions of Siberia. The operational reliability and in-use performance of overburden dragline excavators determine the mining enterprises’ capacity. The previous studies show that a large percentage of the failures of the mechanical equipment used in opencast mining is connected with the draglines. Reduction of the dynamic load in the kinematic elements of the ESH 20.90 lifting drive increases the operational reliability of the excavators operating in arduous conditions. The statistical analysis has shown that most of the excavators’ breakdowns are connected with the failures of their traction and lifting mechanisms. Therefore, to increase the draglines’ reliability, it is necessary to limit the load on the kinematic elements of the mechanical structure in the periods of the year with a significant temperature gradient. For this purpose, a standard closed-loop control system of the lifting electric drive has been modelled. The modelling has shown an unacceptable level of the dynamic loads arising in the kinematic elements of the excavators operating at low temperatures. As a result, an advanced lifting drive control system for the ESH 20.90 excavator has been developed. The system allows to control the engine torque by the speed, and to stabilize the sustained power of the drive. The study has shown that the suggested system significantly reduces the dynamic stress in the mechanical elements and therefore, increases the excavator’s operational reliability. The application of the developed control system for the lifting drives of dragline excavators has been substantiated.

The purpose of the study has been to create a compact and mobile excavating machine that allows permissible-dilution mining of thin bed strata and seams with different rise angles, and thus, cleaning-up of the mineral reserves both in quarries and underground mines. The article analyzes the known mining machinery and technologies used to extract mineral raw materials from thin bed seams in both opencast and underground mining. Geohods are considered promising mining machines as they make it possible to create significant pressure on the face by using the workings’ contour as a support structure for the power loads. The paper presents a geohod structure developed for mining mineral reserves in thin bed ore bodies, and the technology of its application. It is an autonomous device consisting of a frame with guides and hydraulic cylinders, and double disc cutters with supporting sheets and pushers. The double disc cutters of the geohod create pressure on the face due to the frame expansion in the workings, the loosened rock mass being removed with a pneumatic conveying system. Thus, the machine structure is simplified in comparison with the known geohod structures. The power supply and control of the geohod are realized from an external module located on a quarry face or in an underground mine working. The layout of the geohod mill unit allows rectangular cross-section workings, resulting in a high extraction factor. The extraction technology using geohods provides an economic ground for cleaning-up the reserves of thin bed ore bodies.

The aim of the study has been to define the changes in the physical-mechanical properties of cement stone when adding different-concentration silica fume (SF) of different grades, and to experimentally compare the obtained values with the state standard (GOST) permissible values. Different-concentration cement slurry was mixed, with a 48-hour interval for thickening and solidification before the test. The obtained cement stone was tested for compressive and flexural strength using a hydraulic press; besides, its water separation and spreadability measurements were taken. Based on the experimental data analysis, the dependence of the cement stone’s strength properties on silica fume admixture was defined, and conclusions were drawn on the permissible amount of SF in the cement slurry. With the SF concentration exceeding 8%, the cement slurry no longer meets the standard values and becomes low workable and highly viscous. The article discusses the possibility of improving the cement stone properties in well construction for hydrocarbon deposits development. A series of experiments have been carried out with the purpose to modify the cement of PCT - 1-50 grade with silica fume admixtures of MK-65 and MK-85 grades. The reagent was chosen due to its ability to influence the strength and permeability of the cement stone, as well as the water separation, sulfate resistance, and density of the cement slurry. On the basis of the study done, it has been concluded that the above admixtures do influence the strength properties of the stone; though to increase the flowability of the cement slurry, further experiments are needed. A properly selected admixture can reduce the cement slurry’s viscosity, thereby making it possible to achieve the consistency meeting the production requirements.

The purpose of the study has been to substantiate, develop and test the methodological, methodical and technological principles of geoinformation mapping for monitoring the geological environment of the Angara water reservoirs. The research methodology is based on the concept of morphosystems that makes it possible to classify the relief and identify its dynamic hierarchy at three levels of generalization: morphostructure, basin, and slope. Based on the shoreline morphosystems maps, a morphodynamic analysis of the shores has been conducted, and the erosion rate has been determined. The information component of the morphosystems mapping is a computerized database containing survey, cartographic, and reference data. The main sources of information are remote sensing and field instrumental observation data from the model sites. The technological component is geoinformation mapping that allows modeling and dynamic analysis of the shoreline morphosystems at different scale and time levels. The ‘reservoir influence zone’ concept has been defined from the point of view of the morphosystems dynamics. For mapping purposes, the reservoir shores have been classified. The potential use of satellite images for decoding the morphosystems has been evaluated. A specific content of the compiled maps has been created. A system of system of notation conventions for the morphosystems’ maps has been developed. Authoring maps of the influence zone morphosystems for the Angara reservoir cascade have been compiled. A method of morphodynamic analysis of the reservoir shores has been developed and tested. The retrospective and prospective morphodynamic analysis of the model sites have defined the erosion rate in the past, present and future. The results of the study infer that based on the geoinformation mapping and morphodynamic analysis of the shoreline morphosystems of the reservoir influence zone, prompt monitoring of the geological environment can be done for large artificial water reservoirs such as the Angara cascade reservoirs.

The aim of the study is to evaluate the effectiveness of X-ray diffraction analysis (XRD) and differential scanning calorimetry (DSC) used in the study of clay minerals. Due to the small particle size of clay minerals, XRD and DSC are considered most effective research methods. As a qualitative analysis for some kaolinite minerals is still a challenge, the authors present the results of a mineral composition analysis for three types of clays, i.e. VN 01 (Vietnam), Laos 02 (Laos) and NZ 03 (New Zealand) in order to evaluate the effectiveness of the two above-mentioned methods. The results show that the XRD method appears to be relatively effective in a qualitative analysis as well in distinguishing kaolinite and dickite from halloysite. As the diffraction peaks of kaolinite and dickite are quite close, it is difficult to differentiate between the two minerals, while kaolinite-dickite or dickite-halloysite pairs are easily distinguished by DSC due to their different endothermic effects. Kaolinite and halloysite have identical endothermic effects ranging from 530°C to 590°C which makes it difficult to differentiate between them using DSC. XRD method is effective in a qualitative analysis of clay minerals in general, and of kaolinite minerals in particular. It is also effective when distinguishing between kaolinite and halloysite, which is impossible when using DSC; though it is of a limited effectiveness when differentiating dickite and kaolinite. To improve the effectiveness of clay analysis for other research objects and to evaluate the quality of kaolin or other high-disperse minerals, combination of XRD and DSC methods is suggested.

The aim of the work has been to introduce a new method in the soil microstructure study for the clay and loess soils uncovered by well-drilling in the right-bank junction zone of Academic Bridge / Academichesky most, Irkutsk. The microstructure information block is usually unavailable in engineering-geological survey, though it is often one of the leading factors in evaluating the soil properties. Along with the study of the soil microstructure, the data on the soil plasticity has been used in the predictive calculations of the plasticity number at the yield point, in order to further substantiate the proposed method. Using the "Microstructure" method, the total aggregate content has been defined, including the prevailing fine fine-sandy, primary (unbound) fine-sandy, primary coarse-dust, and fine-dust particles; real clay content (clay fraction content in a free and aggregate state) has also been defined. In the course of the statistical data processing, the average values of the above parameters contents have been calculated, and their variability in the studied object group has been estimated using the variation coefficient. The soil skeleton-aggregated microstructure type defined by the total aggregate content shows a high real content of the clay fraction. Based on the average values of the selected parameters content, a special graph has been plotted, that reflects the parameters ratio for the studied objects. The comparison between the plasticity number values calculated by the predictive formulas and the experimental data shows a high matching degree in relation to the soil designation by the standard classification.

The aim has been to study the geotechnical conditions of certain ore deposits occurring in a permafrost zone, with the focus on the stress-strain properties of the rocks mass. The study was conducted in 2000-2018 at the Laboratory of Geomechanics and Rock Physics, INRTU. The main physical-mechanical properties of the rocks and ores have been defined in accordance with the requirements of the Russian Federation standards. The characteristics were selected based on the most common methods of estimating the geotechnical conditions of ore deposits, and on the stress-strain calculation for the structural components of the filed development systems. The analysis of the rock stress-strain characteristics has been carried out with the account of the main structural and cryogenic features of the ore deposit rock mass, and of rock outcrop in the mine workings. The study has distinguished three types of geotechnical conditions: permanent-frozen rock zone, frozen-to-thaw rock transition zone, and permanent-thaw rock zone. When evaluating the ore deposit geotechnical conditions, a differentiated approach to determining the rock stress-strain properties is suggested: natural dry state for the permanent-frozen rock zone; water-saturated state after 25 freezing-thawing cycles for the transition zone; natural dry and water-saturated state (depending on the hydrogeological factors) for the permanent-thaw rock zone. It is suggested that the conversion of the sample rock strength properties into those of the rock mass is done using the differentiated coefficient of structural slackening with the account of the permafrost, rock jointing, and the mining’s’ geometrics. When evaluating the burst risk and the brittle fracture susceptibility, the rock cryogenic state should be taken into account. It is recommended that the brittle fracture susceptibility is defined by either of the following methods: by the Kuznetsov criterion (the ratio of the rock’s compressive strength to its tensile strength), by out-of-limit deformation (the ratio of the rock’s modulus of elasticity to its modulus of decrease), or a by combination of the two. Based on the research results, a series of methodological and normative documents have been developed for regulating the rock pressure and defining the geotechnical parameters for the conditions of cryolythozone ore deposits underground mining.