A method for predicting the stress-strain state of the lining of underground structures, the shape of the cross-section of which is different from the circular outline, is considered. The main task of the study is to develop a methodology for assessing the influence of the parameters of the cross-section shape of underground structures on the stress state of the lining. To solve this problem, a method for calculating the stress state of the lining for arched tunnels with a reverse arch and quasi-rectangular forms is substantiated and developed. The methodology was tested, which showed that the accuracy of the prediction of the stress state of the lining is sufficient to perform practical calculations. An algorithm for multivariate analysis of the influence of the cross-sectional shape of underground structures of arched and quasi-rectangular shapes on the stress state of the lining is proposed. Parametric calculations were performed using the developed algorithm and regularities of the formation of the stress state of the lining of underground structures for various engineering and geological conditions, as well as the initial stress state field, were obtained. A quantitative assessment of the influence of geometric parameters of tunnels on their stress-strain state was performed.
The paper is dealing with a developed concept named Empowerment Teaching, which is based on practical teaching experience gained in various mining universities. It is demonstrated that this concept can be used to increase the effectiveness of knowledge transfer to mining countries in the world, as well as to overcome cultural barriers between lecturers and their students. The two models of participatory training, which are proposed to be named “physical” and “emotional” models, are portrayed. The authors are convinced that participatory training methods can be an ideal answer to a challenge associated with workers’ competencies in mining, namely – the potential of highly motivated and well-educated young academics is often diminished by a lack of ability to apply their knowledge. A special emphasis is made on the possible application of empowerment teaching for educational and training activities in the field of occupational safety and health (OSH), which is a matter of utmost importance for the mining industry. Several benchmarking initiatives in the field of OSH (“safety culture”, zero-accident vision) are underlined to be encouraged and promoted by means of new teaching methods. The examples of successful international cooperation among universities are given, as well.
The article proposes a method for predicting the stress-strain state of the vertical shaft lining in saliferous rocks at the drift landing section. The paper considers the development of geomechanical processes in the saliferous rock in the landing area, the support is viewed as a two-layer medium: the inner layer is concrete, the outer layer is compensation material. With this in view, the paper solves the problem of continuum mechanics in a spatial setting, taking into account the long-term deformation of salts and the compressibility of the compensation layer. Long-term deformation of saliferous rocks is described using the viscoplastic model of salt deformation into the numerical model, and the crushable foam model to simulate the deformation of the compensation layer. This approach considers all stages of the deformation of the compensation layer material and the development of long-term deformations of saliferous rocks, which makes it possible to increase the reliability of the forecast of the stress-strain state of the vertical shaft lining.
Based on the analysis of the mining and geological conditions for developing coal deposits in Vietnam, the existing mining safety regulations, the application of methods for calculating the air supply of working and development faces using the methane factor and modern methods of mathematical modeling of the ventilation of mines threr was developed the procedure for analyzing the efficiency of air distribution management considering the proposed indicator - energy efficiency coefficient for ventilation systems, determined by the efficiency of air use and energy consumption. Relations have been obtained that determine the relationship between the aerodynamic resistance of negative regulators, the number of simultaneously developed working and development faces, the performance of main ventilation fans and the consumed electric power.
The article deals with the role of groundwater in methane formation in coal fields of North-East Vietnam using the example of Maohe deposit. Main geochemical processes during groundwater filtration in a coal bed are determined.
