Analysis of Failure Characteristics and Strength Criterion of Coal‐Rock Combined Body with Different Height Ratios

Wang, Tuo; Ma, Zhuang; Gong, Pan; Li, Ning; Cheng, Shixing

doi:10.1155/2020/8842206

Cited by 9 publications

(4 citation statements)

References 27 publications

(24 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…e coal samples were selected from the standard specimen made of coal blocks in a coal mine in Shanxi Province of China. e coal blocks obtained from the underground were processed into standard cylindrical coal samples with a diameter of 50 mm and a height of 100 mm by using drilling, cutting, and grinding [22][23][24]. e experimental coal samples are shown in Figure 2.…”

Section: Sample Preparation and Test Methodsmentioning

confidence: 99%

Study on Lateral Deformation and Failure Characteristics of Coal Based on Different Confining Pressures

Ren

Wei

Shu

et al. 2021

Shock and Vibration

View full text Add to dashboard Cite

To study the lateral deformation characteristics of coal under different confining pressures, coal compression experiments with confining pressures of 0 MPa, 3 MPa, 5 MPa, and 7 MPa were conducted under the same loading rate by using the TAW-2000 electrohydraulic servo rock mechanics experimental machine. The results of the study showed the following: at the initial stage of loading, the lateral strain of coal was about 12.22%–46.9% of the axial strain at the elastic deformation stage and 41.18%–64.96% of the axial strain at the inelastic deformation to peak stress stage. Compared with the experiment under 0 MPa confining pressure, the growth rate of the lateral strain of the coal under 3 MPa, 5 MPa, and 7 MPa confining pressures was much smaller than that of the corresponding axial strain. When the coal was damaged under different confining pressures, the lateral strain was maintained at about 0.6 × 10−2. Based on the field verification, we proposed that the lateral strain during the coal failure and the nonlinear region of the lateral axis ratio changing with time can be used as potential parameters for predicting the coal failure.

show abstract

Section: Sample Preparation and Test Methodsmentioning

confidence: 99%

Study on Lateral Deformation and Failure Characteristics of Coal Based on Different Confining Pressures

Ren

Wei

Shu

et al. 2021

Shock and Vibration

View full text Add to dashboard Cite

show abstract

“…With increasing coal-rock ratio, the failure degree of the test piece gradually decreased, and the fracture form gradually changed from fragmentation to collapse. Wang et al [20] conducted conventional triaxial compression tests on coal-rock combinations with different high coal-rock ratios, studied the stress and deformation characteristics of coal-rock combinations, and analyzed the test results under different strength criteria. Huang and Liu [21] analyzed the influence of the loading and unloading rate and path on the mechanical properties of composites of coal and rock.…”

Section: Introductionmentioning

confidence: 99%

Failure and Acoustic Emissions of Coal–Rock Combinations with Different Dip Angles in the Shaqu No. 1 Coal Mine

Fu,

He,

2023

Advances in Civil Engineering

View full text Add to dashboard Cite

The force and deformation characteristics of the rock layer on the top and bottom of the coal seam change significantly when the dip angle changes. The mechanical properties and damage characteristics of differently inclined coal–rock assemblages were investigated, and the results were combined with acoustic emission information, including acoustic emission ringdown counts, to quantify the damage of inclined coal–rocks under compression. The experimental results showed that the stress‒strain curves of the inclined coal–rock assemblages had four main stages, with approximately similar curves in the early stage and deformation in the later stage. The damage gradually changed from shear damage to interfacial slip damage, and the damage area gradually transitioned to the structural surface from coal body components. The cumulative acoustic emission energy tended to decrease with increasing inclination angle, and the peak acoustic emission energy gradually decreased. When the inclination angle was less than 30°, the cumulative energy of acoustic emissions increased slowly, then decreased, and it finally decreased significantly between 30° and 45°; from 0° → 15° → 30° → 45°, the energy change rates were +3.0%, −25.1%, and −78.2%, respectively. For coal–rock assemblages with different interfacial angles, the sliding damage instability caused by the coal–rock interface increased with increasing interfacial angle within the assemblage. The results of this study provide a deeper understanding of the mechanical properties of coal–rock assemblages with different inclinations and the characteristics of fissure extension. The fractal dimension based on particle number decreased with increasing loading rate, and the larger the loading rate was, the smaller the fractal dimension. In addition, the current findings provide a reliable foundation for further understanding the mechanisms of disasters caused by coal–rock disturbances, such as excavation of inclined roadways and extraction of gas, as well as supporting the development of methods for monitoring, early warning, and prevention and control of these types of disasters.

show abstract

“…Several previous studies carried out uniaxial compression tests on coal-rock combinations with different rock-coal height ratios to study the influence of rock-coal height ratio on the mechanical properties and progressive failure mechanism of coal-rock combinations. These studies found that the macroscopic failure initiation stress, peak stress, uniaxial compressive strength, and elastic modulus of coal-rock combinations appear as the rock-coal height ratio decreases [12][13][14][15]. Wu et al conducted an experimental analysis and theoretical verification of rock-coal-anchor (RCB) composite material systems from different angles, and found that the failure of rock-coal composite specimens was caused by tensile and shear cracks, and the reinforcement formed in the composite material system after anchoring limited the areas where cracks might appear in the specimens [16].…”

Section: Introductionmentioning

confidence: 99%

Mechanical Properties of Rock–Coal–Rock Composites at Different Inclined Coal Seam Thicknesses

Wang

et al. 2022

Front. Phys.

View full text Add to dashboard Cite

A comprehensive understanding of the mechanical properties of coal and rock sections is necessary for interpreting the deformation and failure modes of such underground sections and for evaluating the potential dynamic hazards. However, most studies have focused on horizontal coal–rock composites and the mechanical properties of inclined coal–rock composites have not been considered. To explore the influence of different confining pressures and inclined coal seam thicknesses on the mechanical properties and failure characteristics of rock–coal–rock (RCR) composites, a numerical model based on the particle flow code was used to perform simulations on five inclined RCR composites at different confining pressures. The results show that the mechanical properties and failure characteristics of the RCR composites are affected considerably by the inclined coal seam thickness and the confining pressure. (1) When the inclined coal seam thickness is constant, the elasticity modulus of the inclined RCR composite increases nonlinearly with the confining pressure at first, and then remains constant. At the same confining pressure, the elasticity modulus of the inclined RCR composite decreases nonlinearly with the inclined coal seam thickness. (2) When the confining pressure is constant, the peak stress of the inclined RCR composite decreases with the increase of the inclined coal seam thickness. When the inclined coal seam thickness is constant, the peak stress increases with the confining pressure. (3) As the inclined coal seam thickness increases, the peak strain of the inclined RCR composite first decreases rapidly, and then remains constant when there is no confining pressure. When the confining pressure is between 5 and 20 MPa, the peak strain of the inclined RCR composite gradually increases. (4) In the absence of confining pressure, there are few microcracks in the rock at an inclined coal seam thickness of 10 mm, whereas all the other cracks are in the coal section. When the confining pressure ranges between 5 and 20 MPa, the failure modes of the RCR composite can be divided into Y- and X-types.

show abstract

Analysis of Failure Characteristics and Strength Criterion of Coal‐Rock Combined Body with Different Height Ratios

Cited by 9 publications

References 27 publications

Study on Lateral Deformation and Failure Characteristics of Coal Based on Different Confining Pressures

Study on Lateral Deformation and Failure Characteristics of Coal Based on Different Confining Pressures

Failure and Acoustic Emissions of Coal–Rock Combinations with Different Dip Angles in the Shaqu No. 1 Coal Mine

Mechanical Properties of Rock–Coal–Rock Composites at Different Inclined Coal Seam Thicknesses

Contact Info

Product

Resources

About