Mechanical Properties and Strength Characteristics of Rock–Coal–Rock Assemblages under Different Peripheral Pressures

Hongda Wang, Jucai Chang (), Tuo Wang (), Hualei Zhang and Yijun Guo
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Hongda Wang: School of Mining Engineering, Anhui University of Science and Technology, Huainan 232001, China
Jucai Chang: School of Mining Engineering, Anhui University of Science and Technology, Huainan 232001, China
Tuo Wang: School of Mining Engineering, Anhui University of Science and Technology, Huainan 232001, China
Hualei Zhang: School of Mining Engineering, Anhui University of Science and Technology, Huainan 232001, China
Yijun Guo: School of Mining Engineering, Anhui University of Science and Technology, Huainan 232001, China

Sustainability, 2023, vol. 15, issue 16, 1-15

Abstract: To investigate the deformation and damage characteristics of internal coal bodies of small pillars under different pressures, rock–coal–rock assemblage samples were subjected to the conventional triaxial compression test to analyze the mechanical behavior characteristics under different pressures. The results showed that, with the increase in peripheral pressure, the peak strength and modulus of elasticity of the assemblage specimens increased, the range of fracture compaction stage gradually decreased, and the specimen was gradually transformed from brittle to ductile. With an increase in peripheral pressure, the residual strength gradually increased, and the strength decay coefficient gradually decreased. The strength decay coefficient decreased the most at 0–10 MPa, and this decrease slowed down after exceeding 15 MPa. When the peripheral pressure was 0 MPa, the damage degree of the coal pillar was larger. With the increase in peripheral pressure, the number of cracks in the coal column increased, the damage degree increased more, and mixed damage characteristics of tension–shear were found. Based on the Hoek–Brown criterion, the strength criterion applicable to the specimen of rock–coal–rock combination was obtained through numerical fitting iteration, which provides an experimental and theoretical basis for realizing the stability control of small coal columns.

Keywords: rock–coal–rock assemblage; conventional triaxial; rock strength attenuation factor; residual strength; Hoek–Brown criterion (search for similar items in EconPapers)
JEL-codes: O13 Q Q0 Q2 Q3 Q5 Q56 (search for similar items in EconPapers)
Date: 2023
References: View complete reference list from CitEc
Citations: View citations in EconPapers (1)

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