A thorough understanding of mining-induced overburden deformation characteristics and the associated stress redistributions are essential to effectively manage complex safety environmental issues that arise from underground mining. This is particular for mining in deep environments. paper presents a numerical modelling study on kilometer-deep longwall coal mine where thick sandstone aquifer situated approximately 200 m above working seam. The adopts special layout with narrow wide pillars...

<title>Abstract</title> In modern industry, the performance of permanent magnet motors is crucial to enhancing efficiency and system reliability. As a key component these motors, quality magnetic tiles directly impacts motor performance. Therefore, ensuring that tile surfaces are free defects essential for maintaining product quality. While traditional visual inspection methods have been widely used, they suffer from limitations in precision stability. Although deep learning has improved...

Abstract One task facing by the geotechnical engineers is to protect workspace in an underground construction/excavation site from various forms of geological disasters, such as water inrush, rock burst, and collapse surrounding rock/soil. In this paper, a combined controlling measure was proposed based on mining environment: method strip has been initially effective against floor failure when above confined aquifer Bucun coal mine, China, however, its ability avoid inrush yet be...

The deformation and movement characteristics of high-level key stratums in overlying strata are important for estimating ground subsidence understanding failure ultrathick during mining. In this study, a distributed optical fiber sensor (DOFS) multipoint borehole extensometers (MPBXs) were collaboratively employed to monitor the situ mining process at working face 130,604 Maiduoshan Coal Mine. DOFS monitoring results showed that distance from advance influence on surface is 219.2 m. shallow...

Pre-driven longwall recovery roadways are commonly adopted for rapid extraction in the high-production mines of Shendong coalfield China.A special roadway, adapting is utilized to adapt roof and floor match roadway.However, severe accidents such as falls support failures frequently occurred where this layout was applied relatively deep coal seams.This posed a serious threat safe production, effective relocation longwalls.By analysing different cases mining conditions, theoretical...

Abstract Mining‐induced voids are the main circulation pathways for underground fluids such as water and coalbed methane. The collapse of these transmits to ground surface, resulting in subsidence building collapse. Accordingly, effective feasible solutions needed control surface subsidence. In this study, a novel technique void filling short‐wall caving zone was proposed better thin coal seam mining. width working face plays key role technique. A maximum value predicted using numerical...

Abstract Safe and efficient mining of shallow coal seams relies on the understanding effective control strata behaviour. Field measurements, theoretical analysis numerical simulations are presented in this study to investigate mechanism behind abnormal behaviour, such as roof collapse severe roadway deformation, that occurs high longwall face-ends under cover. We observed pillars with two sides being mined out become unstable when cover depth exceeds a certain value. The instability pillar...

There is a layer of the unconsolidated confined aquifer (UCA) made non-cemented sand and grit on bed Quaternary thick topsoil in many coal mines east north China. Existing bedrock measures, it poses serious threat to mine safety. Worse, caused supports crushing water inrush disasters (SCWIDs) resulted significant economic losses. Aiming at above problems, this paper adopts simulation experiment, field measurement, engineering detection, theoretical analysis conduct research. The research...

Longwall pier-column backfilling is a partial technique initially designed in thin coal seam mines. With the increase of mining intensity, height and width working face will also increase. It necessary to analyze how changes dimensions influence control effect overburden subsidence backfilling. In this study, model with combination 25 conditions (five different heights (1~3 m) × five widths (80~240 m)) was using FLAC3D (Vision 5.0) numerical simulation. The simulation used varying widths....

In order to study the physical and mechanical properties of sandstone under high-temperature water-cooling cycling conditions, an RMT-150B electrohydraulic servo rock testing system a DS-5 acoustic emission detection analysis were used conduct uniaxial compression tests on after cycles. The deformation, strength, characteristics analyzed different temperatures cycle times. results show that effect caused changes in sandstone. volumetric expansion rate samples first decreased, then increased...

Clear understanding of overburden failure propagation during underground mining is critical in managing safety and environmental issues such as rock burst hazards, groundwater inrush longwall convergency. This paper presents an in-situ monitoring study strain dynamics at a kilometre-deep mine using distributed fibre optic sensing technology (DFOS). A deep borehole was drilled from the ground surface to near seam installed with optical cable detect deformation contiguous fashion. In addition,...