21 research outputs found
Recognition of Strong Earthquake–Prone Areas with a Single Learning Class. Caucasus, М ≥ 6.0
No full textPARAMETERS OF ROCK STRUCTURES FOR UNDERGROUND ORE MINING
No full textThe concept of preservation of the earth's surface from destruction is realized in the present work through regulating the stresses by coordinating the processes of excavating the ore in time and space according to the criterion of stress minimization. Justification of technological solutions that ensure the preservation of the massif and the earth's surface above it due to the phenomenon of residual strength of disturbed rocks is the purpose of the article. The goal is achieved through analysis of mining practices, established behavior patterns of massifs with a discrete gravity-tectonic structural stress field and methods to ensure their stability by creating conditions for locking rocks within the dome of natural equilibrium. It is shown that the geomechanical balance of discrete rock structure is provided due to the residual bearing capacity of naturally and technologically depleted rocks. A solution is proposed for the prevention of critical stresses and their corresponding deformations by dividing the mine field into areas with a flat roofing, within which cost-minimized technologies can be applied. It is recommended to supplement the criterion of repayment optimality with the amount of compensation for damage to the environment. The typification of the mines depending on stability and disturbance of massifs is given. The condition of the solidity of the massif at various stages of existence is formulated - the condition of the geomechanical balance of the geomechanical system. The workings can be typified according to the stability, depending on the size of the structural blocks of rocks in the roof. The new classification of backfilling technologies with taking into account the phenomenon of rock blocks locking is proposed. Due to the residual bearing capacity of naturally and technologically depleted rocks, under underground mining of deposits there are rock constructions whose properties are corrected by dividing the mine field into geomechanically balanced sections with flat roofin
Natural endogenous factors of geoecological transformation of the mountain part of North Ossetia
No full textGeoecological transformation of the biocenosis habitat is an evolutionary process, predetermined by the interaction of the lithosphere with the hydrosphere, atmosphere and the solar system as a whole, under the condition of anthropogenic impact absence. Geoecological transformation occurs under the influence of many natural factors of an endogenous and exogenous nature, the effects of which in the mountainous areas are especially intensive and damageable, due to the sharp and intense exposure forms of exogenous factors of the erosive destruction, the presence of a large gravitational potential for a spatial removal of the destroyed material, poor protection of the bedrocks by biogeocenosis, low strength of terrigenous rocks, etc. The main factors of the intensive geoecological transformation of the mountain landscape are endogenous geodynamic processes. The Greater Caucasus, as the geosynclinal region of young Alpine orogenesis, is characterized by the active deep geodynamics, the focal zones of which can be activated in time and migrate in the lithosphere, as evidenced by the interchange of the periods of seismic activity and relative passivity of deep geodynamic processes (fault tectonics, seismicity and magmatic manifestations). A high density of the tectonic faults contributes to the weakening of rock strength in the zone of a faulting crop out due to jointing and claying along the friction planes
THE PETROLEUM POTENTIAL ESTIMATION OF THE NORTH CAUCASUS AND KAZAKHSTAN TERRITORIES WITH THE HELP OF THE STRUCTURAL GEODYNAMIC PREREQUISITES
No full textModeling of Coalmine Methane Flows to Estimate the Spacing of Primary Roof Breaks
No full textThe global challenge for the mining sector is the problem of “decarbonization” of coal mining. The modeling of emission flows of coalmine methane is stipulated by the need to prove the environmental effect of the implemented technological changes. For longwall geotechnology, the dynamics of methane concentration in the gas–air mixture extracted by the degassing system reflects the complex relationship between emission and geomechanical processes in the rock mass. In this regard, the aim of the work was to improve the methods for assessing the steps of caving the main roof when mining gas-coal seams. The method of work consisted of processing experimental data (smoothing—Loess, three-dimensional interpolation, regression—the method of least squares) to obtain reliable response functions in three-dimensional space. When developing algorithms in the Python language, the Vi Improved text editor was used. Graphical representation of the results was carried out in “Gnuplot”. As a result of modeling, it was found that the increase in the span of the main roof from 83 to 220 m (S = 1340–1120 m) in the distance range of 120 m in front of the stoping face line and up to 50 m behind it (L = −120–50 m) leads to an alternating cyclicity of local extrema of the dynamics of methane release, according to a polynomial dependence. This fact is a consequence of the implementation of deformation-wave processes in geo-environments, which produce cyclic nonlinearities in the nature of the aero-gas regime of mine methane emissions into anthropogenically disturbed rock masses. In addition, the influence of the situational geomechanical conditions of the excavation area in the goaf was clarified. This makes it possible to reliably identify the caving steps of the main roof
Assessment of the Influence of Astronomical Cyclicity on Sedimentation Processes in the Eastern Paratethys Based on Paleomagnetic Measurements Using Discrete Mathematical Analysis
No full textThe introduction of modern methods for the mathematical processing of geological data is one of the promising areas of study and development in the field of geosciences. For example, today mathematical geology makes it possible to reliably identify astronomical cycles by measuring the scalar magnetic parameters of rocks (magnetic susceptibility). The main aim of this study is to develop a mathematical tool for identifying stable oscillation cycles (periods) in the dataset of the magnetic susceptibility of rocks in a geological section. The author’s method (algorithm) is based on the concept of discrete mathematical analysis—an innovative mathematical approach to the analysis of discrete geological and geophysical data. Its reliability is also demonstrated, by comparison with the results obtained by classical methods: Fourier analysis, Lomb periodogram, and REDFIT. The proposed algorithm was applied by the authors to analyze the material of field geological studies of the Zhelezny Rog section (Taman Peninsula). As a result, stable cycles were determined for the Pontian and Lower Maeotian sedimentary strata of the Black Sea Basin (Paratethys)
Integrated Earthquake Catalog of the Ossetian Sector of the Greater Caucasus
No full textThis article is the continuation of a study by authors to create the most complete and representative earthquake catalogs with a unified magnitude scale. The catalog created of the Ossetian sector of the Greater Caucasus (the territory of the Republic of North Ossetia–Alania and adjacent areas) was formed by the aggregation of all available data from Soviet, modern Russian, and Georgian catalogs, as well as the data from the International Seismological Centre. The integration was carried out using the author’s approach based on the modified nearest neighbor method. The integrated catalog of the Ossetian sector of the Greater Caucasus contains 16,285 events for the period 1962–2022. For all events, magnitude estimates are reduced to a unified “proxy-MW” scale. The integration of data from various sources made it possible to significantly replenish the beginning of the aftershock sequence of the Racha earthquake with MW = 7.0, which occurred on 29 April 1991. There has been a change in the level of registration over time. Thus, there is a significant lack of events for the periods 1967–1970 and 1988–1991; starting from 1995, the catalog is complete for magnitude 3.2, and since 2005 for magnitude 2.2. The integration of Soviet and modern Russian and Georgian catalogs made it possible to significantly increase the completeness and representativeness of seismic events in the studied Ossetian sector of the Greater Caucasus. This once again demonstrates both the fundamental importance of merging seismic data from global, national, and regional catalogs and the effectiveness of the author’s developed method
Strong Earthquake-Prone Areas in the Eastern Sector of the Arctic Zone of the Russian Federation
No full textThis paper continues the series of publications by the authors on the recognition of areas prone to the strongest, strong, and significant earthquakes using the FCAZ system-analytical method. The areas prone to earthquakes with M ≥ 5.5 in the eastern sector of the Arctic zone of the Russian Federation were recognized. It is shown that certain potential high seismicity zones are well confined to the boundaries of the Eurasian, North American, and Okhotsk tectonic plates. In addition, according to the results of the FCAZ recognition, some areas located at a sufficient distance from the main tectonic structures of the studied region were also recognized as highly seismic. The results of the study, among other factors, justify the use of the assessment of the completeness magnitude in the catalog for choosing the set of recognition objects for the FCAZ method
Development of the Algorithmic Basis of the FCAZ Method for Earthquake-Prone Area Recognition
No full textThe present paper continues the series of publications by the authors devoted to solving the problem of recognition regions with potential high seismicity. It is aimed at the development of the mathematical apparatus and the algorithmic base of the FCAZ method, designed for effective recognition of earthquake-prone areas. A detailed description of both the mathematical algorithms included in the FCAZ in its original form and those developed in this paper is given. Using California as an example, it is shown that a significantly developed algorithmic FCAZ base makes it possible to increase the reliability and accuracy of FCAZ recognition. In particular, a number of small zones located at a fairly small distance from each other but having a close “internal” connection are being connected into single large, high-seismicity areas
Integrated Earthquake Catalog III: Gakkel Ridge, Knipovich Ridge, and Svalbard Archipelago
No full textThis paper represents the final part of a series of studies aimed at creating the most reliable and representative earthquake catalog covering the Russian and European Arctic. The earthquake catalog of the Gakkel and Knipovich ridges, as well as the Svalbard Archipelago with a unified magnitude scale, was formed based on the combination of four regional Russian catalogs and the ISC catalog. The merging of catalogs was carried out using the modification of the author’s methodology, which allowed for the identification of records in different datasets related to the same seismic event. The modification was introduced due to significant changes over time in the source catalogs. The unified proxy moment magnitude scale was formed based on regression analysis of the different magnitude estimates provided by various agencies. The integrated catalog included 17,922 earthquakes that occurred during the period 1962–2022. Analysis of the integrated catalog showed that the level of registration in the studied area significantly varies over space and time. Before 1995, the catalog contained only strong and moderate earthquakes, and the magnitude of complete registration Mc was 5.0 in the Gakkel Ridge, 4.7 in the Knipovich Ridge, and 4.5 in the Svalbard Archipelago. The number of recorded events increased in the period 1995–2011, and Mc decreased to 4.0 in the Gakkel and Knipovich ridges and to 2.8 in the Svalbard Archipelago. The best level of registration in the Svalbard Archipelago and the Knipovich Ridge was achieved after 2012, when Mc reached 1.7 and 2.8, respectively. In the Gakkel Ridge, despite a noticeable increase in the number of reported events from 2012, the magnitude of complete registration did not improve and was 4.0. The presented integrated earthquake catalog is intended for a wide range of studies of the seismic regime of the Arctic
