“Double Peak” of Dynamic Strengths and Acoustic Emission Responses of Coal Masses Under Dynamic Loading

Feng, Xiaoting; Ding, Zeng; Ju, Yunqiang; Zhang, Qiming; Ali, Muhammad

doi:10.1007/s11053-022-10066-3

Cited by 45 publications

(20 citation statements)

References 53 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…According to many researchers [30][31][32], the laboratory and in-situ evidence was that under the superposition of static and dynamic load, the originally existed minor fissures in coal and rock mass will initiate, converge and connect into macro-fracture, eventually led to the failure of coal and rock mass. Specifically, the general complete stress-strain curve is divided into five stages, as shown in Fig.…”

Section: Introductionmentioning

confidence: 99%

Microseismic fuzzy comprehensive evaluation method of coal burst - A case study in Zhaolou Coal Mine

Zhang,

Liang,

Lin

et al. 2024

Preprint

View full text Add to dashboard Cite

Based on a coal burst in LW 1305 and combined with the curve of stress vs. strain, six multi-parameters are proposed to forewarn coal burst induced by static high-stress concentration and impact loading, containing microseismic (MS) activity S value, fault total area A(t) value, lacking of shock b value, statistical Z value, MS entropy value and the dominant frequency. The precursors mainly characterize the enhancement trend of S value, the suddenly and sharply rise of A(t) value, the continuous and abnormal lower b value, the increasing absolute value of Z sharply and large than 2, the continuous and abnormal decline of Qt value, and the dominant frequency moving to low-frequency band, respectively. The coal burst in LW 1305 was induced by the intrinsic static high-stress concentration and the external strong impact loading generated by fracturing of the key stratum. Essentially, a lot of micro-fissures inside the key stratum had initiated, converged and connected to form the macro-fracture above LW 1305, which was verified by the attenuation rate of K value. Considering the time-varying effect of the overlying stratum movement, the curves of the six multi-parameters have a good agreement with that of stress vs. strain, which indicates it is reasonable to take the observed zone as a whole system to investigate variation of the multi-parameters and fracturing of the key stratum. It is noteworthy that the MS multi-parameters should be combined with reasonable mining arrangement and corresponding prevention measures to monitor, forecast and control coal bursts in the field.

show abstract

Section: Introductionmentioning

confidence: 99%

Microseismic fuzzy comprehensive evaluation method of coal burst - A case study in Zhaolou Coal Mine

Zhang,

Liang,

Lin

et al. 2024

Preprint

View full text Add to dashboard Cite

show abstract

“…Consequently, knowing the saturation impact on the coal fracture behavior is very valuable in evaluating the stabilizing of rock structures and preventing damage to them. Acoustic emission (AE), often referred to as stress wave emission, is the abrupt strain energy release in the form of an elastic wave during material deformation [27][28][29]. Researchers have extensively investigated AE waveforms and the link between AE signal performance and the mechanical process of coal failure [30].…”

Section: Introductionmentioning

confidence: 99%

Analytical Damage Model for Predicting Coal Failure Stresses by Utilizing Acoustic Emission

Ali

Wang

et al. 2023

Sustainability

Self Cite

View full text Add to dashboard Cite

Overburden collapse and water inrush in mines are primarily caused by rock fractures. Mining safety can be enhanced by monitoring and identifying early signs of coal failure in the mines. This article collected acoustic emission data synchronously throughout a series of uniaxial compression (UC) experiments on natural and water-saturated coal. The influence mechanisms of water, mechanical properties, and acoustic emission signals on the stress–strain curve and the SEM results of water-saturated and dry samples are investigated. As a result, the mechanical properties of coal are not only weakened by water saturation, such as elastic modulus, strain, stress, and compressive strength but also reduced acoustic emissions. In comparison with saturated coal, natural coal has a uniaxial stress of 13.55 MPa and an elastic modulus of 1.245 GPa, while saturated coal has a stress of 8.21 MPa and an elastic modulus of 0.813 GPa. Intergranular fractures are more likely to occur in coal with a high water content, whereas transgranular fractures are less likely to occur in coal with a high water content. An innovative and unique statistical model of coal damage under uniaxial loading has been developed by analyzing the acoustic emission data. Since this technique takes into account the compaction stage, models based on this technique were found to be superior to those based on lognormal or Weibull distributions. A correlation coefficient of greater than 0.956 exists between the piecewise constitutive model and the experimental curve. Statistical damage constitutive models for coal are compatible with this model. Additionally, the model can precisely forecast the stress associated with both natural and saturated coal and can be useful in the prevention of rock-coal disasters in water conditions.

show abstract

“…A coal burst is a dynamic failure phenomenon driven by energy. Therefore, it is better to reveal the essential characteristics of coal bursts by studying the energy evolution law [20][21][22][23]. In the research on the stiffness theory of coal bursts, limited by the test methods, the research on the energy parameters in the current stage is less and generally only involves the analysis of the storage and release of elastic strain energy in the two states of the peak strength point and post-failure [19].…”

Section: Introductionmentioning

confidence: 99%

Simulation Research on Energy Evolution and Supply Law of Rock–Coal System under the Influence of Stiffness

Yin

Tang

et al. 2023

Sustainability

View full text Add to dashboard Cite

The energy supply effect caused by the stiffness difference between roofs and sidewalls is an important factor that induces strain coal bursts. In order to quantitatively reveal the energy supply mechanism of strain coal bursts, this paper first establishes a coal burst energy model of the rock–coal system and proposes the calculation formula of coal burst kinetic energy considering supply energy and the stiffness ratio of rock to coal. Then the whole energy evolution law of the rock–coal system with different stiffness ratios is researched by using the numerical simulation method, and the whole process is divided into three stages. With the decrease in the stiffness ratio, the elastic strain energy of the coal changes little, while its kinetic energy is negatively correlated with the stiffness ratio in a power function. Meanwhile, the elastic strain energy and kinetic energy of the rock have power function relations with the stiffness ratio, too. When the rock–coal system is fractured, the kinetic energy of the coal comes from the release of elastic strain energy from the coal and the energy supplied from the rock. The energy supply rate is between 22% and 35% when the stiffness ratio changes from 3.0 to 0.5, and they show a linear relationship, while the supplied energy has a negative power function relationship with the stiffness ratio.

show abstract

“Double Peak” of Dynamic Strengths and Acoustic Emission Responses of Coal Masses Under Dynamic Loading

Cited by 45 publications

References 53 publications

Microseismic fuzzy comprehensive evaluation method of coal burst - A case study in Zhaolou Coal Mine

Microseismic fuzzy comprehensive evaluation method of coal burst - A case study in Zhaolou Coal Mine

Analytical Damage Model for Predicting Coal Failure Stresses by Utilizing Acoustic Emission

Simulation Research on Energy Evolution and Supply Law of Rock–Coal System under the Influence of Stiffness

Contact Info

Product

Resources

About