The dissertation on reception of the scientific degree of Candidate Technique Science on a specialty 05.15.02 – «Underground mining of mineral deposits». Dnipro University of Technology, Dnipro, 2021.
The dissertation is devoted to the substantiation of rational parameters of mining technology by a single system of several working faces using one transport and ventilation chain. As an example of the solution, a new substantiation of the rational parameters of the technology of mining very thin shallow coal seams for specific mining and geological conditions of the Lviv-Volyn coal basin is given in the manuscript. As a result of theoretical and industrial studies, variable geometric parameters of the reference zone in front of the working faces were established; the assessment of the stress-strain state of the rock mass is carried out; the necessary power parameters for the fastening of mechanized complexes and preparatory workings have been established.
Application of the application information package SolidWorks made it possible to adequately reflect the results of modeling the state of the rockmas in compliance with the principles of dynamic, kinematic and static similarity. An important element in creating such models was that it became possible to estimate the field strength of the selected extraction column with the scale of geometric parameters according to the conversion factors that allow to ensure identity between the corresponding dimensions of the simulated object and ob
(static similarity). The conducted experimental mine researches allowed to confirm the theoretical researches carried out by means of the mentioned package of information programs, results of analytical and test investigations.
It has been reported that the establishment of the physical and geometric parameters of the zone of the support vise is brought up to the value of the change parameters Хі (parameters of the expansion of the zone and the support vise) and σmaxi (the value of the maximum external stress) at input stable total values of wallfaces length (l1; l2). Established a regularity for the maximum amount of stress in the support zone (σmaxi) by the length of the extraction column, which varies logarithmically depending on half the length of the pair unit wallfaces (dl0). This pattern allows to obtain data on the nature of the stress distribution in front of the working faces at their position 0-0 (double-unit wallface). That will provide without emerge operation of paired wallfaces at their compulsory or extremely stop.
According to the results of the performed researches it is established that the half-distance between two paired wallfaces (l), which is a measure of the influence of a geomechanical system is described by a multivariate function of influencing factors (f(x), f(m, j, γ, σ); forms separate sectors of characteristic stress-strain characteristics of the rockmass, which, when taken out of static equilibrium by mining operations, are transformed into kinetic energy of loads for fastening of preparatory workings. Taking into account this function makes it possible to establish zones along the preparatory workings with the appropriate power characteristics of the fastening for effective control of rock pressure while intensifying the processes of extracting work by the simultaneous operation of two paired wallfaces.
The characteristic zones of rock pressure manifestation along the paired wallfaces and preparatory workings used as the transport and ventilation network for two simultaneously worked units are substantiated. Also, schemes of situational management, technical and technological support of mining operations are collected, processed and supplemented, which allow to adequately respond to structural changes in the rock mass and stress state condition.
The obtained results were introduced into the development of technological projects of coal extraction by mechanized complexes (passports of coal mining and preparatory workings support) at the mines of Join Stock Company “Lvivvuhillia”, which allowed the concentration the mining processes in the form of simultaneous operation of several wallfaces within a separate section of the mine field. This made it possible to ensure economically feasible sizes of paired wallfaces (in some cases the double unite operations) and completeness of coal mining, reduce its cost, increase the efficiency of mining equipment usage and increase safety in the face.
The offered technological solutions give the possibility to obtain the expected average economic effect up to 140 (41) million UAH for one excavation area when two (all) preparatory workings are not reused.
