Substantiating and Assessing the Stability of the Underground System Parameters for the Sawn Limestone Mining: Case Study of the Nova Odesa Deposit, Ukraine

Due to the russian federation aggression against Ukraine, the infrastructure of many settlements has undergone significant destruction, so in the post-war period, limestone can become a reliable and useful resource for its reconstruction. A significant number of limestone deposits in southern Ukraine are suitable for the production of wall (block) stone, but the geotechnical conditions of many mining sites require the use of an underground mining method. To study the mining system parameters of the Nova Odesa sawn limestone deposit, analytical and calculation methods are used based on known and proven hypotheses of stable spans and pillars, as well as verification by numerical modeling based on the finite element method in the SolidWorks software package. It has been determined that with a change in the ceiling thickness by 50% (from 0.8 to 1.2 m), the safe width of the chamber in the absence tensile stresses in the sawn limestone roof, under given mining-geological and mining-technical conditions of mining operations, increases by 22%. It has been revealed that the area of 25.0 m2 corresponds to the required safety factor of the square-shaped supporting pillar. It has been shown by numerical modeling that under the conditions of the Nova Odesa deposit, the load on a 5x5 m supporting pillar will reach 26% of its load-bearing capacity, and the extraction chamber ceiling is in a stable state without the formation of tensile stresses. The research results are useful for substantiating and assessing the stability of the room-and-pillar mining system elements with supporting pillars in the underground mining of sawn limestone or other mineral deposits.