Open-pit mining in the USSR is continuously growing. In 1975, open-pit coal production compared to 1970 will increase by 52.2-55.2 million tons and will amount to 205.5-208.5 million tons, or 30% of the total coal production in the country. In 1980 and 2000, the share of surface coal mining will be respectively 40-45 and about 70% of the total coal production in the USSR. ...

When designing the standards for the consumption of timber for coal mining, it is especially important to correctly determine the consumption of timber for the lining of workings, which is from 50 to 70% of the total timber consumption for coal mining. The purpose of this work is to attempt to provide a method for the theoretical determination of the required density of lining of working faces based on the theory of limiting and equivalent spans developed by V.D. Slesarev. In accordance with this goal, the first two paragraphs of the work provide a brief exposition of the theory of limiting and equivalent spans according to V.D. Slesarev; § 3 provides an application of this theory to the issue of determining the magnitude of rock pressure on the lining of workings with a constant width; § 4 presents the method of successive approximations proposed by the author for calculating the expected pressure on the lining of working faces; § 5 provides a formula for determining the required density of lining of a working face; § 6 provides the results of calculating the pressure according to the proposed method for a specific case of practice—the 1st eastern face at Mine B in the Donetsk Basin.