DOI: 10.18503/1995-2732-2022-20-3-45-53
Abstract
Relevance. The modern trend for supporting mine workings is the use of anchors with a frictional method of fastening. As for operators of subsurface resources in Russia, this is a relatively new technology that has been successfully developed since 2008 by UralEnergoResurs LLC. An increasing number of manufacturers of such type of anchors have determined the need for describing the risks associated with their design features. Having analyzed the factors influencing the anchor parts, the authors determined requirements for main characteristics. Problem Statement. At the stage of choosing the steel grade for bolt shafts, the main parameters are yield strength σ_Т and coefficient of relative elongation δ. The requirement for parameter δ follows directly from a special feature of its installation. The most preferable values provide the approximation of yield strength σ_Т to ultimate tensile strength σ_В. Based on economic feasibility, the value of the coefficient of relative elongation of the shaft material should be less than 25%. Originality. Loads from the reinforced surface of the working are perceived by the bolt shaft through the fixed stop on its end part. Currently, the stop is a ring welded to the bolt shaft. At the same time, strength characteristics of the shaft sharply decrease in the weld zone due to structural changes in steel. A qualitative increase in the load capacity of the stop is achieved by forming it directly from the material of the shaft. Result. The use of a new method of forming the stop provides an increase in the load capacity to values comparable to the load capacity of the bolt shaft. To maintain the bearing capacity for a long period in constant exposure to aggressive mine environment, polymer protective coatings should be used. Practical Relevance. A set of implemented solutions, such as meeting the criterion for choosing a steel grade for the shaft, shaping a stop from the material of the shaft, and applying polymer protective coatings, reduces the risk of losing functional properties of the friction roof bolting.
Keywords
roof bolting, bolt shaft, stop, corrosion resistance, shaft profile
For citation
Zubkov A.A., Kalmykov V.N., Kulsaitov R.V., Kutlubaev I.M., Neugomonov S.S., Turkin I.S. Risk Assessment of Supporting Surfaces of Workings with Friction Roof Bolting. Vestnik Magnitogorskogo Gosudarstvennogo Tekhnich-eskogo Universiteta im. G.I. Nosova [Vestnik of Nosov Magnitogorsk State Technical University]. 2022, vol. 20, no. 3, pp. 45-53. https://doi.org/10.18503/1995-2732-2022-20-3-45-53
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