Location of Opening-Out Cross-Cuts in Relation to Rockburst Hazard Conditions along the Face in the Light of Model Testing

Chlebowski, Dariusz; Zorychta, A.; Burtan, Zbigniew; Cała, M.

doi:10.1515/amsc-2017-0009

Cited by 4 publications

(4 citation statements)

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“…With the continuous increase of mining depth and in-situ stress, mine dynamic phenomena or disasters such as mine earthquake, rock burst, coal and gas outburst, and support dynamic load are becoming more and more serious [1][2][3][4][5][6]. Relevant studies show that the range of overburden movement and stress field related to dynamic disasters in deep mining has exceeded the range of traditional basic roof in the longitudinal direction.…”

Section: Introductionmentioning

confidence: 99%

Dynamic Response Analysis of Roadway Surrounding Rock Induced by Dynamic Load under the Action of Hard and Thick Rock Stratum

Liang

et al. 2023

Geofluids

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In the process of coal seam mining, there are often hard thick key layers in the overlying strata. Due to the high strength and good integrity of the hard thick key layer, after the hard thick key layer is broken, the overlying strata will collapse and lose stability in a large area, which is very easy to induce dynamic disasters such as rock burst, mine earthquake, coal wall caving, and roof slab caving. Aiming at the hard and thick key layer overlying the working face, the dynamic response of the mine under the strong mine earthquake induced by the breaking of the main key layer of high-level magmatic rock is numerically simulated and analyzed by using FLAC2D numerical simulation software, and the variation laws of the stress field, displacement field, and velocity field of the coal seam roadway under different boundary conditions and different focal heights are studied. The research shows that the roof of solid coal roadway is prone to vibration in a small range, and the displacement increases and decreases with the disturbance. The displacement of the floor and two sides of the solid coal roadway and the top floor and two sides of the roadway along the goaf continues to increase in the initial stage of the disturbance, and the displacement will remain stable with the continuation of the disturbance. The displacement of both sides and roof and floor of gob roadway can reach stability in the later stage of disturbance, and with the increase of the number of adjacent goaf, the longer it takes for the displacement of surrounding rock to reach stability. When the focal height is lower than 90 m, the variation of surrounding rock response increases sharply with the decrease of focal height. When a strong earthquake occurs in the low rock stratum, the impact damage of roadway surrounding rock is almost inevitable. The influence degree of strong earthquake on the stability of roadway surrounding rock is arranged as follows: gob-side roadway (mined out on one side) > solid coal roadway (mined out on both sides) > solid coal roadway (mined out on one side). The evolution process also shows that the working face boundary conditions have an important influence on the energy propagation of mine earthquake. With the increase of the number of adjacent goafs, the faster the energy attenuation rate of mine earthquake propagation is. The research results have important reference significance for the safe mining of working face under similar geological conditions.

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Section: Introductionmentioning

confidence: 99%

Dynamic Response Analysis of Roadway Surrounding Rock Induced by Dynamic Load under the Action of Hard and Thick Rock Stratum

Liang

et al. 2023

Geofluids

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“…In addition to the material properties of coal and rock, the geomechanical environment is also an important factor influencing the dynamic instability of coal and rock. Among them, geologically weak planes, such as faults or coal seam bifurcations, are the direct cause of local stress anomaly, failure, and instability in the stope 4 – 8 . Formation of coal seam bifurcation is related to the crustal movement, geographical environment, and plant accumulation in coal formation period, and it generally appears as that a single coal seam is gradually divided into two coal seams along transverse direction.…”

Section: Introductionmentioning

confidence: 99%

Research on instability characteristics and precursory effect of coal-rock parting-coal structures

Liu

Wang

et al. 2022

Sci Rep

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The slip and instability mechanisms of coal-rock parting-coal structures under uniaxial loading conditions were investigated using experiments and case verification. The slip and the corresponding precursors were described by monitoring the displacement, strain, and acoustic emissions (AEs) of coal and rock parting blocks during testing, and the experimental results were verified by analyzing the microseismic (MS) effects during the working face advancing in a coal seam bifurcation area. The main conclusions were as follows: (1) each slip of the discontinuities sandwiched between coal and rock parting produced shear and tensile cracks, but the shear cracks was dominant; (2) for the instability mode that was characterized by low peak stress, high energy release, and a stable b value of AE, each slip corresponds to a peak frequency of AE, which can reveal the final instability mode; (3) the sudden drop in the fault total area of AE can be regarded as a precursor for the warning fracture or slip instability of a discontinuity; and (4) the MS events in the coal seam bifurcation area were mainly characterized by a wide frequency and high amplitude, especially near the coal bifurcation line, where there were obvious characteristics of low-frequency shear fracture for the MS events. This study is relevant for the early warning of coal-rock dynamic disasters triggered by the slip, fracture, and instability of coal-rock parting compound structures in coal mines.

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“…In the complex mining environment, coal and rock are under long‐term high loading condition, and internal damage degree of coal and rock is more serious compared with that in shallow mining zone. The normal mining disturbance is also easy to induce the deformation and fracture of coal and rock mass and then causes serious hazards, such as rock burst, coal and gas outburst, and large deformation of surrounding rock 1,2 . Therefore, studying the characteristics of deformation and fracture process of coal and rock under load, mastering the internal damage of coal and rock in advance, and then taking targeted measures can effectively prevent or reduce the occurrence of coal and rock dynamic disasters.…”

Section: Introductionmentioning

confidence: 99%

Experimental investigation on time‐frequency evolution characteristics of electromagnetic radiation below ULF reflecting the damage performance of coal or rock materials

Yang

Rui

et al. 2021

Structural Contr & Hlth

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As a form of energy dissipation, electromagnetic radiation (EMR) is gradually becoming a mainstream method prediction method for damage monitoring of coal and rock. To better improve the prediction accuracy of EMR, it is crucial to investigate time-frequency characteristics of EMR and the influence of coal and rock properties on EMR that occurs in the fracture process. In this paper, the deformation and fracture process of raw coal, shaped coal, and cement specimens under compression are observed, and time-frequency evolution characteristics of EMR below ultralow frequency (ULF) under different loading stages are evaluated. Then, the inherent reasons of time-frequency evolution of EMR reflecting the damage performance are analyzed. Meanwhile, the effect of loading condition and composition and structure of materials on EMR is discussed. Results show that there is obvious EMR below ULF in the deformation and fracture process of coal and rock materials, and the combined denoising method of ensemble empirical mode decomposition (EEMD) and wavelet is suitable for extraction of EMR. Besides, the amplitude is approximately inversely proportional to frequency of electromagnetic signals, and the relationship between pulse count of EMR and damage is related to the homogeneity of coal and rock materials. Moreover, the time-frequency characteristic parameter of EMR, such as amplitude, pulse count, and frequency spectrum, can indirectly reflect the damage evolution process of coal and rock. These results can provide a theoretical basis for remote monitoring of coal and rock dynamic disaster using EMR below ULF.coal and rock materials, damage evolution j EEMD, electromagnetic radiation, timefrequency characteristics | INTRODUCTIONThe safe development of the coal industry is crucial to the economic lifeline and energy security of the country, especially in coal-dependent countries such as China, India, and South Africa. With the increasing mining depth, high

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Location of Opening-Out Cross-Cuts in Relation to Rockburst Hazard Conditions along the Face in the Light of Model Testing

Cited by 4 publications

References 0 publications

Dynamic Response Analysis of Roadway Surrounding Rock Induced by Dynamic Load under the Action of Hard and Thick Rock Stratum

Dynamic Response Analysis of Roadway Surrounding Rock Induced by Dynamic Load under the Action of Hard and Thick Rock Stratum

Research on instability characteristics and precursory effect of coal-rock parting-coal structures

Experimental investigation on time‐frequency evolution characteristics of electromagnetic radiation below ULF reflecting the damage performance of coal or rock materials

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