Sergey Markov

Quarry automobile transport is most important in the transportation of overburden and coal in open-cast mining operations. In this article, based on the existing analysis of the use of classic haul trucks, the change in their output is determined by some influencing factors: the type of loading of the rock mass and the bucket capacity of the excavator used. It is taken into account that when loading an unmanned dump truck, there is no need to maneuver the vehicle, which increases output, especially with a small haulage arm. Some output calculation results are given and areas for further research are identified.

Automobile transport currently dominates the transportation of overburden and coal at open pit mines. Its share has been steadily growing since the 1970s. This is due to objective reasons, first of all, a rather limited area of application of railway transport: a significant transport distance, a large cargo traffic and a small depth of the quarry. First of all, it concerned the depth of open-cut mines, because when deepening the quarry for one trench it was necessary to extract considerable volumes of overburden to provide accommodation of transport berms because of the big radius of curvature of a railway track, which reached 200 m. Therefore, given the fact that open-pit mining went to a greater depth at almost all enterprises, there was a widespread abandonment of rail transport for intra-pit transportation in favor of automobile transport. For various reasons, a fairly economical and promising mode of transport – conveyor transport – has not become widespread at Kuzbass coal mines. Not least of all, this is due to climatic conditions, as well as the complexity of mining and geological conditions of the Kuznetsk Basin, which are among the most complicated in the world. Suffice it to say that more than 80% of coal seams have a complex or very complex structure. Therefore, the problem of research and description of the key characteristics in open-pit mining is very urgent.

Grain size distribution as a structural characteristic of waste rock and bulk masses in the course of mining and construction works acquires quantitative values in the process of rock blasting and hauling of rock mass. Such physical-mechanical and structural-textural parameters of a rock mass, as the ultimate strength of rocks and rock mass, fracturing, diameter of the natural rock jointing, have a significant impact on the blasted rock mass grain size distribution. On the other hand, such characteristics as stability, permeability of waste rock masses largely depend on the lithology and grain size distribution of the loosened rocks composing waste rock dumps and their height distribution within a dump. The paper describes the findings of the study of the grain size distribution of waste rock masses of Kuzbass coal strip mines and the features of its spatial variations within the masses. The textures of the bulk masses and physical and technical properties of the stacked rocks were studied both at the Kuzbass waste rock sites and in laboratory conditions. The grain size distribution of the fine lump part of the dumps with the lump size up to 50 mm was investigated by sieve method according to GOST 12536–2014, and the medium and large lump part was studied using oblique photoplanimetry. The field observations showed that the bottom part of the rock dumps, dumped by peripheral bulldozer or excavator methods was composed of coarse fraction with average lump size of: dcr = 0.8–1 m, while the middle part, of rock lumps of dcr = 0.4–0.6 m, and the upper part, mainly of fine fraction with lump size of less than 0.1 m. The ratio of length, width, and thickness of the blasted rock lumps was 1:0.85:0.8, which corresponds to elongated-flattened shape of the lumps. This requires significant number of coordinates for describing the lump positions in the rock mass, as well as taking into account the moments of inertia when modeling the motion of such lumps until they reach a stable position. Up-to-date non-commercial or commercial software and corresponding hardware can be used to take into account non-isometric shape of the lumps when modeling their motion.

Исследование вскрытия наклонных месторождений при комбинированной системе разработки на примере Куреинского участка

Ссылка для цитирования Марков С.О., Хорешок А.А., Тюленев М.А. Влияние угла падения трещин на локальное напряженное состояние приоткосной зоны вскрышного уступа // Известия Томского политехнического университета. Инжиниринг георесурсов. – 2021. – Т. 332. – № 12. – С. 211-219. Актуальность. Напряженно-деформированное состояние массива горных пород при открытой разработке месторождений полезных ископаемых, равно как и при строительстве в грунтах выемок значительных размеров, зависит как от механических свойств пород, так и от структурно-текстурных особенностей массива горных пород. В частности, наличие трещин в приоткосной зоне уступа может значительно ослабить его устойчивость, а направление и угол падения трещин относительно откоса уступа изменяют расположение напряженных зон внутри массива относительно поверхности обнажения. Актуальной научно-практической задачей представляется выявление зон повышенных механических напряжений с целью прогноза поведения массивов горных пород с различными структурно-текстурными свойствами. Цель: выявление зон концентрации напряжений в приоткосной части уступа в массиве горных пород с различными структурно-текстурными свойствами при ведении открытых горных работ. Методы: математическое моделирование массивов горных пород с учётом их физико-механических свойств и структурно-текстурных особенностей методом конечных элементов, обработка результатов экспериментальных исследований. Результаты. Приведено описание математической модели упругого поведения естественного трещиноватого массива горных пород, имеющего поверхность обнажения в виде уступа, а также закономерности распределения концентрации напряжений в нём. Описано напряжённо-деформированное состояние нагруженного и ненагруженного массивов в ненарушенном и нарушенном трещинами различной ориентации состоянии. Описано положение зон концентрации растягивающих напряжений, проведено сравнение их значений для уступов с различным строением. Выявлены повышенные значения растягивающих напряжений в массиве при направлении падения трещин от откоса уступа по сравнению с ненарушенным состоянием и при направлении падения трещин в сторону откоса уступа.

The paper describes a method for determining the density and specific surface of the package of rock particles represented by discs with the size corresponding to the size of the rock fragments of real dump massifs (2D case). The packing method of the particles corresponds to the schemes of dumping used in open-pit mining - areal and peripheral ones. The influence of boundaries, in which the dump is located, on the physical characteristics of this massif - density and porosity - is revealed. It was revealed that the way of formation of the bulk of particles affects its density, especially at the boundaries of the massif. The massif of particles formed in accordance with the area technology of dumping has a denser composition and is less affected by the effect of its boundaries than the massif formed in accordance with the peripheral technology of dumping. The applied method of determining the physical characteristics of the bulk medium differs from the statistical methods (e.g., Monte Carlo) and is well-proven for static media, such as dumps and filtering massifs in open-pit mining.

When choosing equipment for working out a coal-bearing zone of a quarry field, one of the most important factors is the use of excavator equipment available at the enterprise. From previously published works, the main advantages and disadvantages of the most common types of excavators (rope shovel and backhoe) are known. In this article, the authors propose an organizational scheme for the development of a coal-bearing zone using both types of excavators. A technological scheme of the development of a coal-bearing and a coalless zone of a quarry field by the complexes of these excavators is given. The advantages of the given scheme of mining are determined.