The support in the bottom-hole zone of the trunk is a system of rings made of monolithic concrete having a different hardening period, which increases from the face up the trunk and is determined by the duration of the tunneling cycle. The strength and deformation parameters of the concrete support depend on the age of the concrete. Thus, to determine the strength of concrete in the early stages of concrete hardening, various empirical dependencies are used that link the strength of concrete at the design age with the strength at the required age. Based on a series of calculations performed by the finite element method, it was found that the change in the penetration rate does not significantly affect the relationship between stresses and deformations when static equilibrium is reached in the ""support – array"" system, which occurs at a high penetration rate at a greater distance from the bottom of the trunk. At the same time, intensive loading of the support at an early age can disrupt the process of natural hardening of concrete, lead to a violation of its structure, the development of fracturing, which will entail a decrease in the bearing capacity and water resistance of the support, a decrease in its durability.
Keywords: shaft, sinking, support, concrete, stress, deformation, strength, bearing capacity
Today in Russia there is an acute problem of processing of waste of the logging and wood processing industry. At almost all stages of timber production, waste is generated, which is disposed of or left to rot. Felling residues obtained in the process of cutting operations are used least of all. Currently, loggers leave up to 30 % of only the stem of trees, primarily low-quality wood, not to mention twigs, conifers, stumps, while logging waste is a valuable raw material that can and should be used for further processing. The article discusses the prospects for the development of the timber industry, including related to the rational use of wood resources. A number of experiments were carried out in order to determine the influence of design and technological parameters of knife equipment on the quality indicators of wood-fiber semi-finished product.
Keywords: insulation material, finishing material, grinding, wood fiber semi-finished product, cutting waste, integrated use of wood, grinding machine