The Roof Support Load Analysis for Pre-Driven Recovery Room Parameters Design

Submitted by generalized experience entry longwall into pre- driven recovery room (PDRR) in foreign and Russian mine.Submitted by research characteristic state parameters of the roof at failed entry. Give a classification of roof collapse at the entrance longwall into PDRR.On the example of longwall panel 5а-10-18 mine Raspadskaya reviewed formation process of stress-strain condition in area for PDRR. Has been modeled process of entry longwall into PDRR in the conditions of heavy roof. Determine the expected load on the anchor and standing support, installed in the PDRR. Assessed the load on the longwall shield. When calculating the loads was taken into account the following parameters: width pre-driven recovery room, number of standing support in the PDRR and especially its placement, the rate of entry longwall into PDRR

Rock Pressure Manifestation in Development Workings Advanced in a Thick Coal Seam

A research of rock pressure manifestations in the seam workings of seam 52 in “V. D. Yalevsky” mine is presented. It is shown that the inspected development workings advanced in a thick seam have a number of peculiarities determining the urgency of their stability research. It is noted that the researches are carried out in the workings subjected to coal extraction influence, as well as in the workings not subjected to that influence. A brief description of the research method including a visual examination of the mine workings and their support elements, instrumental studies of the border rock massif and the theoretical justification of the parameters of rock pressure are given. The following patterns: rock pressure manifestations mostly in the workings sidewalls, a positive time dynamics of rock pressure manifestations, and the increased intensity of manifestations in the workings roof after coal extracting in the face were recorded. The theoretical justification of rock pressure manifestations and the interpretation of the results of instrumental researches are given

Simulation of energy evolution during deformation failure process of the layer-intact structure

To research the failure mechanism of the layer-crack structure of surrounding rock in deep mine roadway, the combination (Layer-Intact structure) of shallow layer-crack coal and deep complete coal was taken as the research object, and the mechanical behavior and energy evolution law of the Layer-Intact structure under uniaxial and biaxial compression were studied by numerical simulation with particle flow code (PFC2D). The results show that: (1) In the Layer-Intact structure, layer-crack specimen is destroyed prior to intact specimen; The degree of fragmentation increases with the increase of confining stress, and decreases with the increase of fissure number; (2) The confining stress and the fissure number have a significant impact on the basic mechanical parameters of the Layer-Intact structure. The peak stress of the structure increases first and then decreases with the increase in the confining stress, and decreases with the increase in the fissure number; (3) When fissure number is constant, the energy ratio of layer-crack specimen (strain energy stored in the layer-crack specimen to the the whole specimen) increases first and then decreases with the increase in confining stress, while the energy ratio of intact specimen (strain energy stored in the intact specimen to the whole specimen) decreases first and then increases. When the confining stress is constant, with the increase in the fissure number, energy storage capacity of the Layer-Intact structure is reduced, the energy ratio of layer-crack specimen decreases, while the energy ratio of intact specimen increases. The research can provide some reference for revealing the energy release for dynamic instability of layer-crack structure

Features of application of polymer and organic fastening compounds in underground mining workings repair operations

Актуальность. Для предупреждения обрушений, вывалов угля и породы в подготовительных выработках при ремонтных работах широко применяются специальные скрепляющие материалы и технологии, обеспечивающие повышение устойчивости пород в кровле, угля в боках, заполнение видимых раскрытых трещин, пустот. Технология химического упрочнения успешно применяется на отечественных и зарубежных шахтах уже более 30 лет. Сущность этой технологии заключается в скреплении неустойчивого массива специальными составами. Область их применения является очень широкой. Известно, что наличие вывалов пород из кровли и боков приводят к образованию куполов, значительному увеличению высоты выработок, образованию глубоких отжимов угля в боках. Наличие куполов, вывалов, глубоких отжимов являются местами слоевых скоплений метана в высоких выработках. В связи с этим скрепляющие составы составляют основу новых технологий при ремонте горных выработок, их перекрепке, ликвидации завалов и куполов. Цель: разработка проектных решений и обоснование параметров упрочнения массива горных пород современными скрепляющими составами при ремонте и восстановлении подземных горных выработок. Методы: натурные исследования, статистическая обработка результатов экспериментальных исследований. Результаты. Рассмотрен вопрос применения скрепляющих материалов при ремонте и перекрепке горных выработок. Произведен комплексный анализ различных по основному скрепляющему компоненту скрепляющих составов, учитывающий их характеристики, область применения и требования к оборудованию для производства работ. Выделено восемь основных групп составов. Предложена технологическая схема упрочнения пород кровли и боков на участках сопряжений подготовительных горных выработок с использованием инъекционного упрочнения полиуретановыми составами.The relevance. Nowadays the special fastening compounds and technologies are widely used to increase the roof and walls rock stability, fill visible open cracks and voids. It can prevent rock or coal collapses and dumps during the repair operations into underground mine workings. The rock chemical fastening technology has been successfully used in Russian and foreign coal mines for over 30 years. The main idea of this technology is bonding unstable massif areas with special compounds. The application area of fastening compounds is very wide. It is well known that the presence of roof and walls rock falls leads to formation of domes, a significant increase in the height of mine workings and to formation of deep coal squeezing in the walls. The presence of domes collapses and deep squeezes are the places of methane accumulations in high workings. It has a current interest in mining when fastening compositions form the new technics for mine workings repair operations. The main aim is rock massif fastening parameters and design solutions development using modern fastening compounds during the repair and recovery of mine workings. Methods: field measurements, statistical processing of results. Results. The paper considers a fastening compounds complex review during the mine workings repair operations. A comprehensive analysis of different fastening compounds in terms of the main bonding component was carried out. It took into account fastening compounds technical characteristics, their application areas and equipment requirements. Eight main groups of compounds were allocated. A technological scheme at workings crossway areas for roof and walls rock fastening using polyurethane compounds injection was proposed