RECONSTRUCTION ON THE VOLTAGE OF THE PRE-SLIDING STATE OF THE TRAGICHOUS MOUNTAIN SLOPE LANDSCAPE «AK KAIN»

The method of reconstruction and investigation of the pre-landslide condition of the tragic landslide «Ak-Kain» of the Northern Tien Shan is proposed. A model and a finite element algorithm for studying the stress-strain state (VAT) of soil sediments of an obliquely layered structure are briefly presented. The established zones and places of accumulation of dangerous stress concentrations along the inclined layer that led to the tragedy are shown. The plots show the found other areas of hazardous stress concentrations prone to destruction.

Formation of technological schemes during working off steeply inclined layers

Purpose. Creation of technological schemes ofdevelopment of steeply inclined layers in the conditions of the formation of edges of deep iron ore pits during the development of deep steeply dipping deposits in order to determine the width of the working platform. The research of the methodology consists in the development of new technological schemes and the use of existing schemes for the development of benches in the conditions of steeply dipping deposits. The next step is determining the width of the working platform, depending on the layout of the main equipment and the sequence of working off the bench. At the same time, the selected equipment allows to determine the parameters of the working platform of bench. For selecting the equipment, four options of equipment were distinguished according to the averaged parameters of modern mining machines, i.e. the method of averaging indicators was used. Findings. New technological schemes have been developed, as well as existing technological schemes have been used to substantiate the width of the working platform during the formation of steeply inclined layers on the deep edges of pits during the development of deep iron ore deposits. A technique was created that allows you to preliminarily determine the width of the working platform using a nomogram that takes into account the height of the bench, one of the options of equipment that can be used in the development of the bench and the scheme of development. The originality. Graphic dependencies were established for determining the width of the steeply inclined layer. These dependencies will be used during the development of the pit edge. Based on the obtained dependencies, taking into account the formation of technological schemes, it is possible to determine in advance what the width of the bench. Also, the complex mechanization (options 1-4) and the scheme with different heights of the bench are used, which allows to determine the most promising schemes of development, and in the future the rate of change in the level of areas of the steeply inclined layer. Practical implications. The possibility was established by a graphical method to determine the optimal width of the working platform or layer on a separate horizon or within a block, using complex mechanization. The results allow to prepare data (mining flowsheet bench (s), a width platform (layer) by selecting the equipment suitable to work on the bench with the corresponding parameters) for further design of the staged development of steeply inclined layers of deep open pits.

On low-Prandtl-number convection in an inclined layer of liquid mercury

This paper reports on a theoretical analysis of convection in an inclined layer of mercury, a common low-Prandtl-number fluid ($Pr=0.025$). The investigation is based on the standard Oberbeck–Boussinesq equations, which are explored as a function of the inclination angle $\unicode[STIX]{x1D6FE}$ and for Rayleigh numbers $R$ in the vicinity of the convection onset. Along with the conventional Galerkin methods to study convection rolls and their secondary instabilities, we employ direct numerical simulations for fluid layers with quite large aspect ratios. It turns out that, even for small inclination angles $\unicode[STIX]{x1D6FE}\lesssim 6^{\circ }$, the secondary instabilities of the basic rolls lead either to oscillatory three-dimensional patterns or to stationary ones, which appear alternately with increasing $\unicode[STIX]{x1D6FE}$. Due to the competition of these instabilities the patterns may show a complex dynamics.

Bidispersive-inclined convection

A model is presented for thermal convection in an inclined layer of porous material when the medium has a bidispersive structure. Thus, there are the usual macropores which are full of a fluid, but there are also a system of micropores full of the same fluid. The model we employ is a modification of the one proposed by Nield & Kuznetsov (2006 Int. J. Heat Mass Transf. 49 , 3068–3074. ( doi:10.1016/j.ijheatmasstransfer.2006.02.008 )), although we consider a single temperature field only.

Spatio-temporal patterns in inclined layer convection

This paper reports on a theoretical analysis of the rich variety of spatio-temporal patterns observed recently in inclined layer convection at medium Prandtl number when varying the inclination angle ${\it\gamma}$ and the Rayleigh number $R$. The present numerical investigation of the inclined layer convection system is based on the standard Oberbeck–Boussinesq equations. The patterns are shown to originate from a complicated competition of buoyancy driven and shear-flow driven pattern forming mechanisms. The former are expressed as longitudinal convection rolls with their axes oriented parallel to the incline, the latter as perpendicular transverse rolls. Along with conventional methods to study roll patterns and their stability, we employ direct numerical simulations in large spatial domains, comparable with the experimental ones. As a result, we determine the phase diagram of the characteristic complex 3-D convection patterns above onset of convection in the ${\it\gamma}{-}R$ plane, and find that it compares very well with the experiments. In particular we demonstrate that interactions of specific Fourier modes, characterized by a resonant interaction of their wavevectors in the layer plane, are key to understanding the pattern morphologies.