True Triaxial Experimental Study of Anisotropic Mechanical Behavior and Permeability Evolution of Initially Fractured Coal

Liu, Yubing; Wang, Enyuan; Jiang, Changbao; Zhang, Dongming; Li, Minghui; Yu, Beichen; Zhao, Dong

doi:10.1007/s11053-022-10150-8

Cited by 29 publications

(9 citation statements)

References 57 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Fractures in coalbed methane reservoirs serve as the places and channels for the occurrence and migration of coalbed methane, and are the main factors controlling the permeability of coal seams. , Moreover, heterogeneity greatly constrains the flow and diffusion of gas within the reservoir. Therefore, the fracture structure is the main object for evaluating the physical properties of coal reservoirs .…”

Section: Introductionmentioning

confidence: 99%

Study on the Complex Electrical Response Characteristics of Loaded Coal and the Control Mechanism of the Main Fracture System Structure

Li,

Xu,

et al. 2024

ACS Omega

View full text Add to dashboard Cite

The structure of coal seam fractures is the main physical property of coalbed methane reservoir evaluation, and the complex resistivity method is a potential geophysical evaluation method for coal seam fractures. In this study, cylindrical coal samples with axial directions perpendicular to the bedding, face cleat, and butt cleat were prepared. The complex electrical parameters of the loaded specimens were tested with test frequencies ranging from 1 Hz to 10 kHz. The complex electrical response characteristics of the loaded coal are summarized, and the control mechanism of the main fracture system structure is analyzed. The results indicated that (1) as the loading pressure increased, the resistance R and the absolute values of reactance X(|X|) gradually decreased, especially in the frequency band where R slowly decreased and the characteristic frequency of X, the decreased amplitude was more significant, and the cutoff frequency of R and the characteristic frequency of X all gradually increased. (2) The complex electrical properties of coal show obvious anisotropic characteristics. Both R and |X| decreased sequentially according to the direction perpendicular to the bedding, face cleat, and butt cleat; the cutoff frequency of R and the characteristic frequency of X all increased sequentially. (3) The dispersion phenomenon of the complex electrical properties of coal is attributed to the induced polarization; the elevated loading stress enhances the polarization effects of the molecular-induced moments of the coal skeleton, and the anisotropic difference of the complex electrical properties is due to the difficulty in the degree of transport of charged particles induced by structural differences of the main fracture system. (4) The resistance R 3 and capacitance X c were selected as the complex electrically sensitive parameters of the loaded coal orthogonal fracture structures. A logarithmic inversion model reflecting the main fracture system structure of coal was constructed. This provides a certain theoretical basis for efficient electrical exploration of coal reservoir fracture structures.

show abstract

Section: Introductionmentioning

confidence: 99%

Study on the Complex Electrical Response Characteristics of Loaded Coal and the Control Mechanism of the Main Fracture System Structure

Li,

Xu,

et al. 2024

ACS Omega

View full text Add to dashboard Cite

show abstract

“…In China, the mining industry is moving towards deep mining which poses additional safety concerns [1]. Deep mining coal seams can result in coal and gas outbursts, rock bursts, and gas explosions due to high stress, high pressure, and high concentration of gas [2][3][4][5].…”

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

“…Furthermore, through field practice, Ning et al [25] obtained the actual failure situation and crack evolution characteristics of floors, which provides real data for the study of floor failure mechanisms. Some scholars use optical fiber sensors to measure the failure depth of the bottom plate [26][27][28].…”

Section: Introductionmentioning

confidence: 99%

Support Control Design of Mining Roadway under Goaf of Close-Distance Coal Seam

2023

Sustainability

View full text Add to dashboard Cite

Coal resources have always been the focus of attention in the field of sustainable development. Based on the problem of surrounding rock control in close-distance coal seams, first, a mechanical model of floor failure was established based on the 29204 working face in Dongqu Mine; the failure mechanism of the floor was revealed by the zero displacement line, and a method to judge the occurrence state of the roof in the lower coal seam was put forward. Furthermore, by FLAC3D numerical simulation software, the mechanical model is verified, and the optimal support parameters are optimized, and the optimal water–cement ratio and grouting pressure are determined to be 0.6 and 3 MPa respectively. The application shows that the roof displacement is reduced by about 73.48% compared with the control group. Compared with the control group, the cable stress decreased by about 50.68%, and the application effect is remarkable. The research results provide an effective solution to ensure the sustainable development of coal resources and disaster prevention.

show abstract

True Triaxial Experimental Study of Anisotropic Mechanical Behavior and Permeability Evolution of Initially Fractured Coal

Cited by 29 publications

References 57 publications

Study on the Complex Electrical Response Characteristics of Loaded Coal and the Control Mechanism of the Main Fracture System Structure

Study on the Complex Electrical Response Characteristics of Loaded Coal and the Control Mechanism of the Main Fracture System Structure

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

Support Control Design of Mining Roadway under Goaf of Close-Distance Coal Seam

Contact Info

Product

Resources

About