Experiment research on overburden mining-induced fracture evolution and its fractal characteristics in ascending mining

Wang, Cheng; Zhang, Nianchao; Han, Yafeng; Xiong, Zuqiang; Qian, Deyu

doi:10.1007/s12517-013-1178-9

Cited by 44 publications

(24 citation statements)

References 2 publications

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“…Pei et al 24 developed a column covering method to analyze fractal characteristics of AE spatial event distributions, which provide information for further study into rock mass fracture mechanisms. Wang et al 25,26 studied the relationship between fractal dimension and rock failure processes and provided a good reference for rock mass stability monitoring in onsite excavations. Fractal dimension values of AE time-series were calculated by Kong et al 27 which revealed microscopic fracturing mechanisms of coalcontaining gas.…”

Section: Introductionmentioning

confidence: 99%

Damage and fractal evolution trends of sandstones under constant-amplitude and tiered cyclic loading and unloading based on acoustic emission

Liang

Zhang

Xie

et al. 2019

International Journal of Distributed Sensor Networks

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It is of significance to study the damage and destruction of rock under cyclic loading in geotechnical engineering. We determined the trends in damage evolution of sandstone under constant-amplitude and tiered cyclic loading and unloading under uniaxial compression. The results of the study show that (1) the variation of acoustic-emission events was consistent with the stress curves and 89% of all acoustic-emission events occurred during the cycling stages. The observed Kaiser effect was more notable in tiered cycling. (2) The damage variable increased sharply in the cycling stages and its increment was 0.07 higher for tiered cycling than constant-amplitude cycling. Sandstone exhibited greater damage under tiered cyclic loading and unloading. (3) Equations for the evolution of the damage variable under the two cycle modes were obtained by fitting of experimental data. (4) The fractal dimensions of the constant-amplitude cycle were larger than those of the tiered cycle. The process of damage and destruction presents a trend of reducing fractal dimension. The damage accumulation of sandstone under tiered cycling was faster than under constant-amplitude cycling. These results provide references for damage and early warning of rock under both constant-amplitude and tiered cyclic loading and unloading.

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Section: Introductionmentioning

confidence: 99%

Damage and fractal evolution trends of sandstones under constant-amplitude and tiered cyclic loading and unloading based on acoustic emission

Liang

Zhang

Xie

et al. 2019

International Journal of Distributed Sensor Networks

Self Cite

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“…layer group, the overburden crack evolution is trapezoidal and the developing height of cracks discontinuously jumps, as the mining width increases. In collapsing zone, crack zone and bending subsidence zone, the development, propagation and closing of cracks were asynchronous and inner similarity (Wang, et al 2015). The crack's fractal dimension of overburden strata generally experiences two periodic change (i.e.…”

Section: Introductionmentioning

confidence: 99%

Similarity simulation of mining-crack-evolution characteristics of overburden strata in deep coal mining with large dip

Wang

Zhenzhen

et al. 2018

Journal of Petroleum Science and Engineering

114

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Figuring out the mining-crack-evolution characteristics of overburden strata is very important to roof control, gas drainage, disaster prevention and high efficient mining. In order to obtain the mining-crack-evolution characteristics of overburden strata in deep coal mining with large dip, in this study, No.1221 coal mining face of Zhao coal mine is chosen as the research object to establish an in-house experiment system of similarity simulation. The experiments could measure the stress and displacement of overburden strata, which can provide useful information to investigate the mining-crack-evolution characteristics, displacement variations and movement characteristics of overburden strata associated the coal mining face. Experimental results show that with the advancing of coal mining face, the scope of gob increases gradually, and formation of the false roof of overburden strata basically reflects the evolution process of collapsing. The overburden strata weight is constantly transferred to the front and rear of coal mining face, which forms the supporting pressures on both sides of coal pillars, and causes the gangue's collapsing in gob. The large dip of coal seam results in pressure disequilibrium in stress-increasing zone. Thus, the stress on the underside of gob becomes larger and larger, while the stress on upper side of gob decreases. The strata separation appears in the overburden strata of roof. Pressure-relief zone is mainly concentrated in the side of outlet roadway. Along the inclination direction of coal mining face, the crack development and strata separation are obvious, which create the passages for gas flow and migration. The similarity simulation results provide fundamental information for better understanding those mining-crackevolution characteristics of overburden strata, which has become more and more important to control the roadway stability in coal mining and optimize the layout of gas drainage boreholes for improving

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“…Feng et al (2008) provided the basic conditions for mining in an ascending sequence: (1) when the overburden is moderately hard, the upper seam should be located above the key strata (the layer that is closest to the lower stope without the development of step-like fractures) in order to avoid damaging the floor; and (2) when the surrounding strata are relatively soft, the upper seam should be positioned inside the water-conducting fractured zone (WCFZ) of the lower stope and subsidence stabilization should precede mining. The distribution of the water-conducting fractures and the feasibility of mining in an ascending sequence have been well studied, providing a reliable basis for mining coal seams in close proximity in an ascending sequence (Jiang et al 2012;Wang et al 2015).…”

Section: Introductionmentioning

confidence: 99%

Overburden Failure Associated with Mining Coal Seams in Close Proximity in Ascending and Descending Sequences Under a Large Water Body

2017

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Experiment research on overburden mining-induced fracture evolution and its fractal characteristics in ascending mining

Cited by 44 publications

References 2 publications

Damage and fractal evolution trends of sandstones under constant-amplitude and tiered cyclic loading and unloading based on acoustic emission

Damage and fractal evolution trends of sandstones under constant-amplitude and tiered cyclic loading and unloading based on acoustic emission

Similarity simulation of mining-crack-evolution characteristics of overburden strata in deep coal mining with large dip

Overburden Failure Associated with Mining Coal Seams in Close Proximity in Ascending and Descending Sequences Under a Large Water Body

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