Powered Roof Support – Rock Strata Interactions on the Example of an Automated Coal Plough System

Abstract

The study summarises the operating characteristics of the powered roof support (shield) used in an automated plough system. Investigated longwall support units were controlled automatically or by section engineers and positioned in the ‘saw tooth’ configuration with respect to the longwall face (automatic mode) or linear to the face. Shield pressure data have been analysed in order to identify the impacts of particular factors on the pressure increase profiles. The analysis was supported by the Statistica software to determine the statistical significance of isolated factors. Equations governing the leg pressure at the given time instant were derived and the roof stability factor ‘g’ was obtained accordingly, recalling the maximal admissible roof displacement method recommended by the Central Mining Institute (Poland). In the current mining practice, its values are used in monitoring of strata behaviour as indicators of shield–strata interactions, particularly in the context of roof control in longwall mining. It is vital that the method used should be adapted to the actual conditions under which the longwall is operated. In the absence of such adaptations, there will be major discrepancies in results. The conclusions section summarises the current research problems addressed at the Department of Underground Mining, in which the support pressure data in longwall operations are used. The first aspect involves the delineation of deformations of a longwall main gate about 100 m ahead of the face. The second issue addressed involves the risk assessment of roof rock caving or rock sliding in the tail gate. Another aspect involves the standardisation of local conditions to support the methodology of interpreting shield–strata interactions in the context of work safety. These methods are being currently verified in situ.

Study on Pressure Relief Mechanism of Hydraulic Support in Working Face under Directional Roof Crack

“…in this study, it should be noted that monitoring the pressure of the hydraulic support also helps to improve the safety level of the working face. This is because the pressure of the hydraulic support can effectively reflect the interaction between the hydraulic support and the rock stratum [42][43][44], which can be used to reflect the caving behaviour of the main roof. By studying the pressure data, the safety and efficiency of the mining face can be improved.…”

Monitoring the Geometry of Powered Roof Supports—Determination of Measurement Accuracy

“…Powered roof supports can be controlled manually or automatically. Automatic control is used in the case of automated mining complexes [7], in which the operation of the mining machine, the powered roof support and the conveyor is synchronized.…”

Optimization of the Process Parameters of Fully Mechanized Top-Coal Caving in Thick-Seam Coal Using BP Neural Networks

“…Although the loads of hydraulic supports should be monitored in the process of fully mechanized top-coal caving mining to ensure continued safe production [4], this method has become the main strategy for thick-seam coal mining because of its low energy consumption, high output, strong geological adaptability and economic benefits [5][6][7]. It has gradually become the main method of thick-seam coal mining in China, Vietnam, Australia, Turkey and other countries [8][9][10][11][12][13][14].…”