Analyzing kinetics of deformation of boundary rocks of mine workings

Kultaev³

et al. 2020

E3S Web Conf.

Problems of maintaining of development the roadways in conditions of the soft adjoining rocks have been considered. The engineering solution for resistance of rigid protection means by building local reinforced zones under these constructions has been suggested. Combination of protection means and reinforced zones has reduced roof rock subsidence. The operation of protection means and reinforced zones as a holistic construction has been viewed on physical and numerical models. Based on simulation results, the efficiency of deepening of protective means below the footwall, the alternative to which can be creation of the reinforced zones in the footwall rocks, has been established. Factors that have to be taken into consideration when setting parameters of a local reinforced zone under the protective means have been identified.

Section: Methodsmentioning

confidence: 99%

Providing resistance of protection means on the soft adjoining rocks

Kultaev³

et al. 2020

E3S Web Conf.

“…At "DTEK Dobropilliavuhillia" LLC [6] the bottom dinting is from 69 to 84% of the length of mine roadways under repair, and at "1/3 Novohrodivka" mine [7] and SE Shakhtoupravlinnia "Pivdennodonbaske No. 1" [8,9] the proportion of the floor displacement in the roof and floor convergence is 65 -70%.…”

Section: Main Partmentioning

confidence: 99%

“…1" mine. These gateroads are characteristic for the mines of prospective coal-bearing areas and reflect the main features of mining, geological and technical conditions of coal seams with unstable roof and floor strata [9]. In The problem has been solved in two-dimensional formulation, since the standing support and the solid under it are elongated in the plan and the stresses are distributed coplanar.…”

Section: Main Partmentioning

confidence: 99%

“…For this purpose, the research results in the maingate 11 of the western longwall development panel of the с 18 seam at Shakhtoupravlinnia "Pivdennodonbaske No. 1" mine [9] have been taken as input data. It was protected by continuous standing supports of b width equal to 1.1 m. The maximum roof rock displacement above the max U standing support made up 41% of the extracted seam thickness and equalled 0.43 m. They occurred on the upper platform of the standing support (Fig.…”

Section: Main Partmentioning

confidence: 99%

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Problems of mining the prospective coal-bearing areas in Donbas

Bachurin

et al. 2019

E3S Web Conf.

The prospective coal-bearing areas of Donbas in Ukraine have been identified. Their development will increase the energy security of Ukraine. It has been suggested that the development of these areas will involve mining the coal seams in a weak roof and floor environment, which are characterized by low compressive strength, lower density and a tendency to plastic deformations. The stability has been assessed of the rocks outcrop on the contour of mine roadways for mines operating in these areas. It has been determined that roof rocks in most of these mines belong to a range of groups from very unstable to moderately stable, and the bottom rocks are, in most cases, prone to swelling. This complicates the intensive prospective areas mining with the use of advanced technologies, as well as secondary support for retained goaf-side gateroads with limited yielding property. The mines have been determined, for which this issue is relevant when mining the seams with further increase in the depth. The mechanism of displacement in the secondary supports and has been exemplified and studied using the numerical method. The obtained results allowed us to substantiate the necessity of developing new technical solutions for the protection of gateroads under conditions of prospective Donbas areas.

“…In order to reduce the cost of roadways and ensure high loads on walls, special attention is paid to excavation systems with the reuse of roadways and efficient ventilation of excavation sites. This solves several complex problems related to the development and implementation of shoring and protection systems [1], providing direct-flow ventilation [2], roof management [3][4][5], monitoring the condition of mine roadways [6]. Particular attention is paid to the development and improvement of methods and means for the protection of preparatory roadways behind the breakage face.…”

Section: Introductionmentioning

confidence: 99%

Determining the efficiency and parameters of rubble strip reinforcement

Surzhenko

et al. 2021

EEJET

The necessity of development and improvement of methods and means for the protection of preparatory roadways, in particular, protective structures, was proved on the basis of ordinary rock with binding surfaces. Analysis of the results of the study on the use of protective structures of ordinary rock and bounding surfaces was performed. It has shown the feasibility of reinforcing rock structures to ensure operational conditions for the protected roadways. Such structures include rubble strips reinforced with partitions made of metal mesh. To determine their efficiency and reinforcement parameters, studies were performed using provisions of structural mechanics, soil mechanics, and bulk media, as well as physical modeling using natural materials. According to the results obtained in the performed studies, the efficiency of reinforcement of rubble strips with a metal grid was proved and a procedure for calculation of reinforcement parameters that need to be considered in designing the above structures was developed. Such parameters include width and height of the strip, class of reinforcement, its diameter and tensile strength, size of the grid cells, angle of internal friction of rocks, and diameter of maximum rock pieces in the strip. It was established that reinforcement of the rubble strip by partitions made of metal meshes can reduce the width of the strip and volume of the rock fill by 1.33…2.66 times without losing the structure rigidity. To do this, the condition of reinforcement strength in grids must be met. It consists of comparing its tensile strength with maximum stresses in the partition. These stresses are determined by the magnitude of the load on the rubble strip from the roof rocks, the diameter of the reinforcement, and the maximum rock pieces, as well as relative extensional strain in reinforcement.