Evaluation of Technical Condition and Durability of Wooden Shaft Guides with Application of Non-Destructive and Semi-Destructive Testing Methods.

This article addresses the issue of the durability of mining shaft equipment elements. Shafts as a transport route are one of the most exploited parts of a mine. Consequently, their components are exposed to high mechanical stresses, which cause the deterioration of their mechanical properties. In the case of shafts with timber components, elements such as the shaft guides are evaluated on a purely macroscopic basis and are often unnecessarily replaced. This paper presents the possibilities for the application of non-destructive methods (ultrasound and laser scanning) and semi-destructive methods (sclerometric and drill resistance tests). The experimental results suggest that it was possible to derive correlations between penetration depth and drill resistance tests with bulk density. However, these tests were not directly correlated with flexural strength. The ultrasound studies did not indicate a significant relationship with the physical or mechanical properties. In contrast, the method of comparing the variation (wear) in the tested guides using 3D laser scanning demonstrated a high accuracy; moreover, this method is independent of factors that may affect the results of penetration depth or drill resistance measurements. The application of non-destructive and semi-destructive tests for the determination of the physical and mechanical properties of timber elements of mine shafts' equipment may enable the detection of a defect earlier or extend the service life of elements, hence limiting the downtime of shaft operation related to the replacement of elements.