Substantiating rational parameters for a stull-timbered device of the selective heading machine

Abstract

Purpose. To carry out the studies of proposed options for overlapping to support excavation roof and ensure roof maintenance to avoid collapse and protect people and mechanisms. To study a specified goal, an expert assessment of the existing tools to maintain roof rocks in the working area where people and mechanisms are engaged has been carried out. Methodology consists in applying software and computer simulation of interaction processes of mining rocks with arched design options. Findings. A short analysis of the most commonly applied structures to provide temporary fastening of preparatory and permanent mine workings has been carried out. The options for a roof design and the elements for temporary fastening are proposed. The parameters for four sectional overlapping have been substantiated. The loads acting on the roof-supporting structure and the coefficients required to determine the rock loads, the strength of some roof layers and "soil" as well as the forces in the rack hydraulic cylinder have been calculated. Originality. Applying temporary arched fastening in the working area of a tunneling machine promotes reducing a number of technological operations and manual labor employment as well as enhancing maintenance personnel safety. The speed of tunneling works is supposed to increase. Practical value. It is based on the analysis of a selective heading machine performance with an easily collapsed roof, study results to achieve a constructive machine improvement are presented. Its components may vary depending on mining and geological conditions of the work. The obtained parameters are verified by calculations and design solutions. The minimum mass of the fastening that provides both rigidity and strength of the structure is significantly reduced. Obtained results can be applied in underground tunneling and other similar works as well as in constructing roads and railways. The design of the device gives the possibility to adjust the height depending on the mine roof condition.