Pore and fracture development in coal under stress conditions based on nuclear magnetic resonance and fractal theory

Zhao, Yu; Wang, Chaolin; Ning, Lin; Zhao, Houfa; Bi, Jing

doi:10.1016/j.fuel.2021.122112

Cited by 124 publications

(31 citation statements)

References 44 publications

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“…Thus, fractal theory was used to analyze the effect of SWP on the pore area fractal dimension of CTB specimens in this study. The pore area fractal dimension of binarized SEM micrographs was determined via box counting (Zhao et al, 2022;Zhang et al, 2020;Wu et al, 2019;Sun et al, 2019). As shown in Figure 9, the changing regularity of SWP on pore area fractal dimension of CTB specimens was similar to SWP on porosity.…”

Section: Effect Of Swp On Pore Area Fractal Dimension Of Ctbmentioning

confidence: 87%

Mechanical Properties and Microstructure Evolution of Cemented Tailings Backfill Under Seepage Pressure

Shen

Chen

et al. 2022

Front. Mater.

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Cemented tailing backfill (CTB) in underground mine inevitably experiences seepage field, which complicates its mechanical behavior. In this study, the mechanical properties and microstructure characteristics of CTB under different seepage water pressures (SWPs) were investigated. The results show that, with the increase in SWP, the mechanical properties of CTB decrease, but the decreasing trend reduces gradually. Higher SWP leads the microstructure of CTB looser and more porous, and the largest proportion of pores initiated and propagated by SWP is micropores, which means the damage in CTB under seepage is mostly caused by micropores. Besides, the mechanical properties of CTB under seepage decrease exponentially with the increase in porosity and present linearly inverse proportional relation to the pore area fractal dimension. Results above indicate that SWP has a significant deterioration effect on the mechanical properties and microstructure of CTB. The research could not only extend the knowledge of mechanical properties and microstructure characteristics of CTB under seepage but also provide a theoretical reference for mechanical index determination and stability analysis of CTB in water-rich underground mines.

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Section: Effect Of Swp On Pore Area Fractal Dimension Of Ctbmentioning

confidence: 87%

Mechanical Properties and Microstructure Evolution of Cemented Tailings Backfill Under Seepage Pressure

Shen

Chen

et al. 2022

Front. Mater.

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“…To improve the flow state of water in the spillway in the paper, a ladder-shaped spillway is proposed for optimization and redesign. Based on the relevant standards and requirements [23,24], a hydraulic simulation model is established and the hydraulic characteristics of the optimized scheme are simulated under different cases [25,26], resulting in a stable flow state of water in the optimized model and a good energy dissipation rate at the downstream chute [27,28].…”

Section: Introductionmentioning

confidence: 99%

The Experimental Investigation of the Optimization of the Flow State of a Ladder-Shaped Spillway in a Certain Reservoir

Zhang

et al. 2022

Geofluids

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The original design scheme of ladder-shaped spillways in certain reservoirs is improved by using a hydraulic similar model experiment. The results of the original scheme demonstrate that the stilling basin cannot meet the requirement of safe discharge, and the flow state at the end of the stilling basin is violent and chaotic. The experimental method of the physical model was used to optimize the design of the spillway without changing the original plane layout. First, three steps in the ladder are added. The stilling basin is then replaced by the torsion plane. Finally, the longitudinal slope of the tail channel section is altered, and an experimental investigation on the flow state and energy dissipation rate is performed. The conclusions are drawn that the flow state of the water is obviously improved, and the energy dissipation rate increases; the optimal scheme produces the expected effects.

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“…The essence of rockburst is the differential distribution of energy caused by mining disturbance and the inevitable result of the dynamic adjustment in the process of quantitative change [12][13]. The existing energy priming theory shows [14][15][16][17] that the formation of rockburst is often highly correlated with the dynamic-static combination. Combined with the actual working conditions, it can be divided into static load-oriented and dynamic loadoriented.…”

Section: Introductionmentioning

confidence: 99%

Coupling Analysis of Water Injection Softening-Precursor Information Prediction of Coal-Rock Mass Based on Energy Conduction

Lai

Cao

et al. 2022

Geofluids

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To further refine the rationality of pressure relief measures, the pressure relief measures are transformed from engineering scale to laboratory scale. In this paper, the static load is applied by uniaxial compression, and the difference in the energy evolution process of loaded coal samples is compared using pressure relief at an indoor scale. The test results show that the pressure relief state of water injection can meet the conditions well and reduce the impact tendency of the whole coal samples. In addition, try to analyze the reasons why it is difficult to accurately predict the formation of rockburst in coal roadway by analytical means. Due to the special structure of coal, it can be found that both natural and saturated conditions can meet the conditions in the state of water injection and pressure relief, while in the dry state, the conditions cannot be met; that is, the precursor signals of disaster cannot be accurately picked up, and finally, the failure of coal samples cannot be accurately predicted. However, on the laboratory scale, the natural coal samples are in the state of adsorption in the air after sampling, and the coal bodies near the deep underground working face tend to have low water content due to the development of pores and fissures and the influence of self-weight of mining disturbance. The research in this paper provides theoretical support for the subsequent determination of pressure relief parameters, and the related research conclusions are of great significance.

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Pore and fracture development in coal under stress conditions based on nuclear magnetic resonance and fractal theory

Cited by 124 publications

References 44 publications

Mechanical Properties and Microstructure Evolution of Cemented Tailings Backfill Under Seepage Pressure

Mechanical Properties and Microstructure Evolution of Cemented Tailings Backfill Under Seepage Pressure

The Experimental Investigation of the Optimization of the Flow State of a Ladder-Shaped Spillway in a Certain Reservoir

Coupling Analysis of Water Injection Softening-Precursor Information Prediction of Coal-Rock Mass Based on Energy Conduction

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