Increasing production efficiency based on active monitoring of bearing capacity of a powered roof support section in a longwall complex

One of the current trends in the technology of supporting capital and preparatory workings is the use of contact grouting. The contact grouting is designed to increase the bearing capacity of the frame supports. The paper considers a method for calculating the support pressure and the displacement of the support crown. The calculation method is based on the interaction of the system of blocks “support – filling layer - broken rock layer - undisturbed rock”. The following factors were taken into account in the method of calculating the frame arch support: depth of the roadway development, mine working cross-section, the support section, the width of the filling layer and its deformation characteristics, as well as the deformation and strength characteristics of the rock mass. Checking of the support strength state is done by comparing the calculated load versus the rated bearing capacity of the support. The developed technique allows making the choice of support in various mining conditions of the application.

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Case Analysis of Damages to Control Hydraulics of the Leg in the Powered Roof Support Section

E3S Web of Conferences ◽

10.1051/e3sconf/201910503013 ◽

2019 ◽

Vol 105 ◽

pp. 03013

Author(s):

Janina Świątek ◽

Kazimierz Stoiński

Keyword(s):

Coal Mining ◽

Case Analysis ◽

Hard Coal ◽

Support Section ◽

Full Extension ◽

Safety Measures ◽

Bench Tests ◽

Hard Coal Mining ◽

Roof Support

The article discusses a case of security hazard in a longwall equipped with a properly selected chock shield support with two legs, technically efficient, introduced to the market and for operation in compliance with the requirements covering Polish hard coal mining. As a cause of the hazard an accidental coincidence was indicated, such as the occurrence of a tremor at an area with unfavourable geometry for the operation of the support section and leg (including the shift of the double-telescopic leg from the 1st to the 2nd hydraulic stage) at the time of the mining process. Immediate safety measures were applied successfully. They were aimed at minimizing the conditions dangerous to the crew. The section was withdrawn and spragged again. As a result, the leg operated in full extension mode of the 1st hydraulic stage, obtaining the required strength and geometry of the section and leg. The presented case study will be additionally supplemented in the future with selected analytical and bench tests.

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To improve the contact adaptability of mechanical roof support

E3S Web of Conferences ◽

10.1051/e3sconf/202126603015 ◽

2021 ◽

Vol 266 ◽

pp. 03015

Author(s):

N. Babyr ◽

K. Babyr

Keyword(s):

Technical Solution ◽

Support Section ◽

Mechanized Support ◽

Geological Conditions ◽

Roof Support

The article proposes a constructive technical solution to increase the contact adaptivity of the mechanical roof support. The developed solution of the mechanized support section is able to adapt to changing mining and geological conditions in the process of excavation of the mining pillar, which increases the efficiency and safety of coal excavation in the longwall.

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Tests of an Innovative Controller Designed to Control the Powered Roof Support

Multidisciplinary Aspects of Production Engineering ◽

10.2478/mape-2018-0029 ◽

2018 ◽

Vol 1 (1) ◽

pp. 223-231 ◽

Cited By ~ 2

Author(s):

Dawid Szurgacz ◽

Horst Gondek

Keyword(s):

Control System ◽

High Efficiency ◽

Response Times ◽

Support Section ◽

Control Block ◽

Basic Part ◽

Control Functions ◽

Basic Functions ◽

The Moment ◽

Roof Support

Abstract The article presents the methodology and results of tests of a prototype controller designed for the electrohydraulic control system of a powered roof support. This controller is the basic part of the developed, innovative control system. The tests were carried out on a custom-designed testing station, equipped with one section of a roof support. The aim of the research was to check the functionality and speed of the controller's response while working with the actual support section. The tested controller and the control system has a modular structure, which greatly facilitates its operation and use. Measurements of control functions were carried out on the controller connected to the electrohydraulic control block. The research mainly focused on determining the period starting from the moment of providing the signal to the moment of switching on the basic functions performed by the support section. The obtained results confirm the assumptions made. The controller's operation is very stable, and its response times are very short. It can therefore be assumed that the tested controller is correctly designed and constructed. This creates great possibilities for its practical application in the built-in system for controlling the roof support. This may be particularly important in the case of high-efficiency longwall complexes, for which wireless control of the support is planned to be used. The presented research methodology and obtained results should therefore be an important source of information in the field of testing controllers for powered roof supports.

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Modelling of Powered Roof Support Cooperation with the Floor of Low Bearing Capacity in the aspect of Shaping the Section Design

Archives of Mining Sciences ◽

10.1515/amsc-2017-0013 ◽

2017 ◽

Vol 62 (1) ◽

pp. 177-188

Author(s):

Józef Markowicz ◽

Sylwester Rajwa ◽

Stanisław Szweda

Keyword(s):

Computer Simulation ◽

Finite Elements ◽

Bearing Capacity ◽

Pressure Distribution ◽

Finite Elements Method ◽

Factors Influencing ◽

Section Design ◽

Simplifying Assumptions ◽

Roof Support

Abstract The problem of cooperation of powered roof support with the floor in the aspect of shaping its design is presented. From the analysis of the simplifying assumptions considered so far in the methods for determination of roof support’s base pressure on the floor, it results that they are not satisfied in the case of bases of the catamaran type, commonly used in currently manufactured roof supports. Model of cooperation of the base lying on the floor, prepared by the finite elements method is described and the results of computer simulation of the base action on the floor are given. Considering the results of numerical analyses, the factors influencing the pressure distribution of the base on the floor as well as its maximal value, have been identified.

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Impact of geometry of the powered roof support section on the rock mass

E3S Web of Conferences ◽

10.1051/e3sconf/20187100001 ◽

2018 ◽

Vol 71 ◽

pp. 00001 ◽

Cited By ~ 1

Author(s):

Dawid Szurgacz

Keyword(s):

Rock Mass ◽

Underground Excavation ◽

Support Section ◽

Correct Operation ◽

Mechanical Elements ◽

Roof Support

The required functions of the powered roof support, the functions it must fulfil and the mechanical elements cause that the support practically continuously works with the rock mass. This applies to the canopy, the floor base and the shield support. Due to the different susceptibility and strength of the rocks, the roof support may lose its stability. This condition results in an uneven section load and difficulties with moving forward the support in the underground excavation. This, in turn, can lead to disturbances in the operation of the entire longwall system. In order to avoid this situation, it is necessary to conduct geometry tests, e.g. section tests for a dedicated testing station using innovative measuring inclinometers. They indicate the importance of proper geometry for proper and correct operation of the support section. The research was carried out with the use of a new methodology designed to test the geometry of powered roof supports. The solutions were developed by the author of the article.

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The impact of selected structural and operational factors on load bearing capacity of the powered roof support

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/261/1/012039 ◽

2019 ◽

Vol 261 ◽

pp. 012039

Author(s):

A Pawlikowski

Keyword(s):

Bearing Capacity ◽

Load Bearing Capacity ◽

Load Bearing ◽

Operational Factors ◽

The Impact ◽

Roof Support

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Tests of Geometry of the Powered Roof Support Section

Energies ◽

10.3390/en12203945 ◽

2019 ◽

Vol 12 (20) ◽

pp. 3945 ◽

Cited By ~ 11

Author(s):

Dawid Szurgacz ◽

Jarosław Brodny

Keyword(s):

Research Area ◽

Measuring System ◽

Analytical Models ◽

Geometrical Parameters ◽

Support Section ◽

New Approach ◽

Operation Process ◽

Geological Conditions ◽

Actual Geometry ◽

Roof Support

A powered roof support is a basic protection mean for longwall excavations in which highly efficient mining is carried out. The support operates properly when its individual sections are spragged correctly in a working and their operating parameters meet specific requirements. The geometry of the section, and in particular, the correct position of the floor base and the canopy, have a significant impact on the parameters and effectiveness of its work. Disturbances in this area, in many cases, are the cause of damage and improper operation of the support. Therefore, a new method of testing the position of the section in a longwall was developed based on an analysis of its geometry. The basis of this method are inclinometers (angle sensors) mounted on the main structural elements of the section. Recorded values of the angles of inclination of these elements and the developed analytical models are used to determine the positioning of the section in a longwall. The main purpose of the research was to develop a method that would allow, in the simplest possible way, the analysis of section geometry in real conditions. A simplified analytical model was used to determine the actual geometry of the section. It was used then as a basis of an analysis of possible states of the position of the section in the mining wall, including the surrounding rock mass. The results were applied during tests of the section carried out in a testing station and in real (underground) conditions. The developed measuring system helped to determine selected geometrical parameters of the section during these tests. The purpose of the research was to verify the developed model and demonstrate that the geometry of the section has a significant impact on its uneven loading. The obtained results, especially from underground tests, confirmed that during operation the support sections are twisted, which may cause overloading of their construction and disturbance of the operation process. The developed method of testing the geometry of the section is a new approach to analyzing the work of the powered roof support operating in variable mining and geological conditions. The developed method of testing the position of the section based on the angle of inclination of its individual elements is undoubtedly a new approach to this research area. The results obtained should be successfully used in practice to optimize the support section and when selecting support for specific working conditions.

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