-
Date submitted2023-06-01
-
Date accepted2024-03-05
-
Date published2024-08-26
Analyzing friction bolts load bearing capacity in varying rock masses: an experimental study in Anti Atlas Imiter silver mining region, Morocco
This study analyzes how key factors impact friction rock bolt capacity using standard pull-out tests, focusing on 39 mm diameter, 180 cm long split-tube bolts. We investigate bolt performance dependence on rock mass rating (RMR), time after installation, schistosity orientation, surface roughness, and installation quality. The aim is optimizing bolt design and implementation for enhanced underground stability and safety. Results show RMR strongly exponentially correlates with pull-out resistance; higher quality rock masses increase capacity. Anchorage capacity significantly rises over time, especially for RMR above 70. Increasing angle between bolt axis and rock foliation from 0 to 90° boosts pull-out response. Reducing borehole diameter below bolt diameter grows bolt-ground friction. Empirical models estimate load capacity based on RMR, time, orientation, diameter, roughness and installation quality. These reliably predict bolt performance from site conditions, significantly improving on basic RMR methods. Experiments provide practical friction bolt behavior insights for typical rock masses. The data-driven analysis ensures models are applicable to actual underground scenarios. This enables tailored optimization of bolting configurations and supports. Methodologies presented should improve safety, efficiency and cost-effectiveness of reinforced mining and tunneling. Overall, this study fundamentally furthers friction bolt performance understanding, enabling superior underground support design.
-
Date submitted2022-10-29
-
Date accepted2023-10-25
-
Date published2024-04-25
Assessment of rock massif sustainability in the area of the underground research laboratory (Nizhnekanskii Massif, Enisei site)
The study presents the results of the research on geodynamic and geological conditions of the Enisei site (Krasnoyarsk Krai), chosen for the construction of an underground research laboratory. The laboratory is being built at a depth of 500 m to assess the suitability of the rock mass for burying high-level radioactive waste. The rocks consist of weakly fractured gneisses, granites, and dikes of metadolerites. Field observations were conducted on bedrock outcrops. They included the determination of rock mass quality indicators, measurement of rock fracturing, and a rating classification of stability using N.Barton's method. GNSS observations were also made to monitor surface deformations. These data were used to develop a three-dimensional structural model, including lithology, fault disruptions, intrusive bodies, elastic-strength properties of rocks, and the sizes of zones influenced by faulting. It will serve as a basis for boundary conditions and the construction of three-dimensional variational models of stress-strain states, identifying zones of concentration of hazardous stresses, and planning in situ geomechanical experiments in underground mines of the laboratory. The obtained values of the modified QR index for the main types of rocks allowed their classification as stable and moderately stable, corresponding to strong and very strong rocks on Barton's scale and the massif rating according to geomechanical classification.
-
Date submitted2008-11-17
-
Date accepted2009-01-28
-
Date published2009-12-11
Rating indicators of the financial condition estimation of mining enterprise
- Authors:
- J. V. Luebeck
The method of receiving of united factor is considered to be the foundation of system development monitoring factors based on integrations of private factors of financial analysis, that is to say calculation of rating for different variants of investment activity a mining enterprise. Calculation of rating of borrower and rating of financial stability has the most importance while developing the investment strategy of development a mining enterprise. Rating analysis will allow to motivate the possibility for calculating the real investments, defining the value of rational growth of production volumes, motivating the borders of rational increase the volumes of production within the framework of investment activity.
-
Date submitted2008-11-16
-
Date accepted2009-01-30
-
Date published2009-12-11
Social and ecological responsibility of mineral and raw materials companies
- Authors:
- A. O. Kharchenko
In this article the author describes the basic concept of the corporate social responsibility, analyzes main features and standards of making of social reports of major companies. Specificity of reports in the Russian companies is allocated, and some offers with a view of activization of promotion both further ordering CSR and the eco-reporting in the Russian Federation on the basis of introducing new administrative and economic methods.