Stadnichuk M. Justification of the parameters and conditions for the use of roadway district protection means in coal mines

Theestablished pattern of pressure of undermined coal seam roof on the means of roadway protection are defended, which made it possible to substantiate rational types and parameters of the protection meansbased on the provisions of the theory of risksand to ensure the reuse of roadway districts in coal mines. A new formula is obtained for calculating the coefficient of the influence of the type of protection means on the roadway districts displacement, which takes into account the risk of the roadway deformation, the coal seam thickness and the angle of its inclination to the horizon and the design parameters of the protection means - its width and locationrelative to roadway. A mechanism is disclosed and patterns of loading and deformation of roadway district protection means made of a quick-hardening mixture are established depending on the time of its hardening and the distance to the longwall face with taking into account the category of the coal seam roof stability. The scientific and methodological basics are developed for using the 3D printing technology to create complex physical models of the rock massif and roadway.Automation of this process ensures high accuracy of geometric dimensions and dosing of model materials, which significantly reduces the error of the end results of laboratory tests. The implementation into production of the recommendations on parameters and technologies for constructing roadway protection means in “Chervonogradska" and "Lisova" mines of the state enterprise "Lvivvugillia"made it possible to reduce the costs of the cement-mineral mixture by 27% and preserve the belt roadways No. 562 and No. 166 for reuse as air roadways while mining the adjacent panel.The results obtained in the dissertation were included in the normative document of Ukraine "Instructions on ensuring the stability of roadway districts for reuse in coal mines"