Strength and deformation of pillars during mining in the shaft pillar

Abstract

first_pagesettingsOrder Article Reprints Open AccessArticle Strength and Deformation of Pillars during Mining in the Shaft Pillar by Jindřich ŠancerORCID,Vladimír Petroš,Vlastimil Hudeček andPavel Zapletal *ORCID Department of Mining Engineering and Safety, Faculty of Mining and Geology, VSB Technical University Ostrava, 17 Listopadu 2172-15, 70800 Ostrava, Czech Republic * Author to whom correspondence should be addressed. Appl. Sci. 2024, 14(12), 5003; https://doi.org/10.3390/app14125003 Submission received: 24 April 2024 / Revised: 31 May 2024 / Accepted: 5 June 2024 / Published: 8 June 2024 (This article belongs to the Topic Complex Rock Mechanics Problems and Solutions) Downloadkeyboard_arrow_down Browse Figures Review Reports Versions Notes

Abstract This study of the strength and deformation of coal samples was triggered by the need to define the stress–strain characteristics of pillars during room and pillar mining in the shaft protective pillar at the ČSM Mine. It was probably the world’s deepest deployment of this mining method in a coal mine. In order to solve the bearing capacity of pillars, the dependence of coal strength on the slenderness ratio is used. For this reason, coal samples with different slenderness ratios were investigated. After considering the purpose of this research, slenderness ratios (width/height) of 1 to 7.7 were chosen. At the same time, the modulus of deformation as a function of the slenderness ratio was determined, and the vertical deformation of the pillars and the safety factor were calculated. Attention is also paid to the influence of sampling on the results of measured coal strengths.