scholarly journals A method for calculating loads on roof support in mines

2021 ◽  
Vol 773 (1) ◽  
pp. 012028
Author(s):  
VM Seryakov
Keyword(s):  
2021 ◽  
pp. 1-21
Author(s):  
Hannah V. Mattson

Dedicatory offerings of small colourful objects are often found in pre-Hispanic architectural contexts in the Ancestral Pueblo region of the American Southwest. These deposits are particularly numerous in the roof support pillars of circular ritual structures (kivas) at the site of Pueblo Bonito, Chaco Canyon, which served as the ceremonial hub of the Chacoan regional system between the tenth and twelfth centuries ce. Based on the importance of directionality and colour in traditional Pueblo worldviews, archaeologists speculate that the contents of these radial offerings may likewise reference significant Chacoan cosmographic elements. In this paper, I explore this idea by examining the distribution of colours and materials in kiva pilaster repositories in relation to directional quadrants, prominent landscape features, and raw material sources. I discuss the results in the context of Pueblo cosmology and assemblage theory, arguing that particular colours were polyvalent and relational, deriving their meanings from their positions within interacting and heterogenous assemblages.


2016 ◽  
Vol 6 (10) ◽  
pp. 299 ◽  
Author(s):  
Lin Zhang ◽  
Zhongbin Wang ◽  
Chao Tan ◽  
Lei Si ◽  
Xinhua Liu ◽  
...  

2019 ◽  
Vol 105 ◽  
pp. 01030
Author(s):  
Vladimir Tarasov ◽  
Anatoly Fomin

The paper considers a new type of powered roof support unit in the framework of interaction with geomechanical processes within the ground rock, particularly, in the thermodynamic balance capsule. Its novelty in comparison with similar Russian and foreign technologies consists is in the fact that geomechanical system “support–ground rock” is brought into the state of balance, which increases the safety of mining works at a coal extraction face.


2021 ◽  
Vol 1 (2) ◽  
Author(s):  
Dawid SZURGACZ ◽  
Sergey ZHIRONKIN ◽  
Konrad TRZOP ◽  
Stefan VÖTH ◽  
Leszek SOBIK ◽  
...  

A powered roof support protects people and equipment in the longwall from potential dangerposed by the surrounding rock mass. The study to determine the position of the powered roof supportwas conducted in an active longwall. The research team made measurements of the geometric height ofthe powered roof support structure located in the longwall complex. The main objective of this studywas to determine the position of the powered roof support in actual underground conditions. Theanalysis of the results provided data on whether the assumed height of the longwall was maintainedduring operation of the complex.


2018 ◽  
Vol 1 (1) ◽  
pp. 361-368
Author(s):  
Dawid Szurgacz ◽  
Jarosław Brodny

Abstract Mining machines suitable for hard coal mining, due to the specifics of this industry must be characterized by very high technical parameters. In particular, it concerns their durability, reliability and availability. Currently used machines approved for operation in underground conditions meet such requirements. Nevertheless, during their operation it is reasonable to conduct supervision and control of work parameters. This applies to both machine manufacturers and users, which is especially important in the event of a failure. Mine employees should be able control of the entire operation process. This control can be effective thanks to a visualization system developed to monitor the working parameters of mining systems. The paper discusses the innovative system and presents the results of efficiency tests. They concerned the visualization of the operation of a powered roof support. The obtained results indicate that the assumed goal of the system has been achieved. The system is built on elements of industrial automation, which guarantees the reliability of the indicated values. Its graphic layout and selection of the presented parameters are also approved. It should also be emphasized that the system can work with currently operating systems and is easy to expand. According to the Authors, the system should find a wide application in practice.


2018 ◽  
Vol 29 ◽  
pp. 00006 ◽  
Author(s):  
Dawid Szurgacz ◽  
Jaroław Brodny

A powered roof support is a machine responsible for protection of an underground excavation against deformation generated by rock mass. In the case of dynamic impact of rock mass, the proper level of protection is hard to achieve. Therefore, the units of the roof support and its components are subject to detailed tests aimed at acquiring greater reliability, efficiency and efficacy. In the course of such test, however, it is not always possible to foresee values of load that may occur in actual conditions. The article presents a case of a dynamic load impacting the powered roof support during a high-energy tremor in an underground hard coal mine. The authors discuss the method for selecting powered roof support units proper for specific forecasted load conditions. The method takes into account the construction of the support and mining and geological conditions of an excavation. Moreover, the paper includes tests carried out on hydraulic legs and yield valves which were responsible for additional yielding of the support. Real loads impacting the support unit during tremors are analysed. The results indicated that the real registered values of the load were significantly greater than the forecasted values. The analysis results of roof support operation during dynamic impact generated by the rock mass (real life conditions) prompted the authors to develop a set of recommendations for manufacturers and users of powered roof supports. These include, inter alia, the need for innovative solutions for testing hydraulic section systems.


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