Home – Home – Jornals – Advanced Search

Experimental fracturing is carried out in rock samples of different strength, taken in the same borehole but at different depths. From the analysis of acoustic emission from fracturing of the rock samples under quasistatic loading, the spectral composition of acoustic emission signals is determined in the samples in elastic, plastic and soft straining before failure. Microcracks initiated in early loading generate high-frequency signals. As loading is increased, the spectrum expands toward lower frequencies with opening of existing cracks and initiation of new cracks. The values of the energy release intensity during acoustic emission in samples under quasistatic loading up to failure are given. The introduction of the specific energy release coefficient of acoustic emission in fracturing of the test samples enables ranking the samples by their mechanical properties. The thermal fields mapped on one of the test samples under varied quasistatic loading allow judging on the behavior of the internal stresses in the sample.

Using the input impedance method, the basic characteristics of electromagnetic wave reflection in multilayered media are theoretically calculated. Numerical modeling and physical simulation helped estimate amplitudes of GPR waves reflected from layers in a multilayered medium, and the reflection coefficients were determined for every layer of different thickness.

The hydrogeological and geochemical situation in underground mining at the Tyubegatan potash deposit, Uzbekistan is analyzed. It is shown that an emergency water ingress in a mine stope has a direct hydrodynamic connection with aquifers in overlying strata above salt strata and with ground surface. Water ingress is a brine resulting from permeation of rainfalls in overburden along vertical cracks connected with a fault developed along the mine mainways. The change in the hydrogeological regime within a local emergency zone and the induced activation of salt karst are discussed.

The article describes in-situ geomechanical observations over deformation in the rock mass-support system in the conditions of the post-limit stress-strain behavior of rock mass at the Almaz-Zhemchuzhina deposit of chromite ore (stability categories IV-V). The methodology framework was monitoring of convergence of stope walls using a band extensometer at 27 deformation stations set both inside and outside influence zones of stoping. Two modes of deformation were identified: background deformations (rate to 1.37 mm/month) and induced deformations with the increased rate of convergence to 72 mm/month (2.4 mm/day). It is found that the extracted ore volume and the displacement velocities are interrelated. An increase in the monthly average volume of ore drawing from 40 to 80 Kt increases the average rate of convergence by 30% (from 0.65 to 0.92 mm/day). The critical deformations are recorded, leading to failure of shotcrete lining, which governs transition to the predictive-preventive stability control in mine stopes.

The geology and geomechanics of the Altai-Sayan Mountainous Region are studied. Deep faults are identified, displacements along which activate seismicity in neighborhood of the rock-burst hazardous Tashtagol and Sheregesh deposits. The influence of large-scale mining operations on the intensity of geodynamic phenomena at great depths is studied. The patterns of earthquakes in the vicinity of the test deposits are examined. The energy classes of blasts (2.5-8.0) and geodynamic phenomena (2.0-6.5), as well as their magnitudes (1.5-2.9) are determined. The scope of the study embraced the influence of blasting on the formation of zones of rock disintegration (I), induced jointing (II) and micro-jointing (III). It is found that the maximal sizes of zones I-III during heading operations are, respectively, 0.48, 1.68 and 4.44 m; these values in blasting using grammonite M21 and an emulsion explosion are, respectively, 2.19 (1.9), 3.84 (3.33) and 15.34 (13.64) m. Using the microseismicity method, the location of the nearest concentration zones of shocks with a seismic energy of 2·10²-10⁷ J in the mine field during blasting in roadways and stopes at a distance of 3.33-15.34 m is determined.

Blasting-induced seismic impact on guarded objects is discussed as a case-study of the Novosmolinsky deposit of granodiorites. Efficiency of seismic safety designs is validated, the actual ground conditions coefficients and ground-motion attenuations are determined with regard to seasonal variations. Based on the ground motion monitoring at guarded objects, the regressional relationships are found between the PPV values and the reduced distances, which enables prediction of levels of blast-induced impacts. The influence of seasonal fluctuations is determined: the ground condition coefficient and seismic attenuation factor increase under negative temperatures, which requires adjustment of mass of explosive charges and distances to guarded objects in the winter period. The formulas are proposed for the calculation of seismically safe parameters of blasting designs with regard to soil temperatures. The results prove the relationship proposed by Academician M. A. Sadovsky, and expand its application range with regard to seasonal factors. The obtained equations improve accuracy of the blasting-induced seismic impact prediction, which allows well-founded adjustment of blasting design parameters and risk minimization at guarded objects nearby.

This article offers an integrated review of an issue of natural and induced landslide initiation by seismic vibrations created by earthquakes and mine blasting toward systematization of present-day research methods of this phenomenon, including numerical, physical and laboratory modeling. The structure of marine landslides is described, and the mechanics of landsliding under the action of seismic waves and the static stability of sea slopes are disclosed. The approaches to estimation of dynamic stability of landslides, as well as the Newmark method and its modifications are described. It is found that under earthquake-induced vibrations, the critical level of accelerations for a sea slope may reach ~ 0.15 g , which is 2 times lower than for a terrain slope. The stability estimate of sea slopes should take into account the pore pressure. An increase of a pore pressure coefficient from 0.1 to 0.4 decreases the safety factor by up to 50%. The published data on in-situ observations over slope failures under the impact of earthquakes and production blasts are discussed. The impact of multiple seismic effects of earthquakes and mine blasting on slopes of hydraulic engineering structures is described.

We take a look at the definition of a halting probability from logical and algorithmic information theoretical points of view.

The article examines the metaphysical foundations of naturalism in relation to consciousness. Naturalism is the most natural and widespread, but not devoid of contradictions, philosophical position. Its weak points are the assertion of the priority of scientific knowledge, while the criteria of scientificity often turn out to be vague; the proclamation of reduction as the main principle, adherence to which can deprive the subject of study of its specificity; denial of the significance of ontological foundations in solving epistemological issues. Naturalism in relation to consciousness, in turn, is faced with the need to assert the ontological status of consciousness: it is a separate ontological entity and then all laws known to science must apply to it, or it is not a separate ontological entity and must be considered as a property of the brain or something similar. Non-reductive naturalism regarding consciousness appears as an internally contradictory philosophical position: by refusing to reduce consciousness to the brain in an attempt to defend the uniqueness of the qualitative qualities of mental states, we thereby violate one of the main postulates of naturalism. It turns out that the ontological status of consciousness cannot be ignored when considering consciousness as a special phenomenon; any of our theories of consciousness directly depend on the definition of this status.

The article offers methodological recommendations for the most accurate tracking of the scientometric index of publication activity and demand for publications of a scientist known in science as the Hirsch index(h-index). The author introduces the developed formula for finding the growth of the scientist's citations added over a certain period of time that affect the increase in the Hirsch index, talks about the parameters of its dependence, gives advice on practical non-automated and automated calculation of the index, describes the scope of its application. The annual, or semi-annual, monitoring of the growth index of active citations, according to the author, is intended to stimulate scientists to further publication activities.