Study on mechanical properties and deformation of coal under different confining pressure and strain rate
ID:475 View Protection:ATTENDEE Updated Time:2022-05-20 10:53:53 Hits:594 Oral Presentation

Start Time:2022-05-27 12:10 (Asia/Shanghai)

Duration:10min

Session:[S10] Resource Development and Utilization of Underground Space » [S10-2] Resource Development and Utilization of Underground Space-2

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Abstract
In order to research the influence of confining pressure and strain rate on the mechanical properties and deformation of coal. The triaxial compression experiments of coal specimens under different strain rate and confining pressure were conducted. In this research, the strength, deformation behavior and failure mode, etc. of coal specimens were evaluated by experiment. The experimental results show that the strain rate mainly impacts peak and post-peak stages of stress-strain curves. The peak strain increases and then levels off with the confining pressure increase at low strain rate. The peak strain increases with the increase of confining pressure at high strain rate, but the increasing rate tends to be reduced. Peak strength, cohesion and internal friction are positively correlated with strain rate, respectively. And there is significant linear correlation between peak strength and confining pressure. For numerical result, macroscopic cracks appear firstly in pre-peak stage under uniaxial compression and firstly appear in peak stage under triaxial compression. Many fine tensile macroscopic cracks appear with the increase of loading at low strain rate and a wide tensile crack and few fine cracks appear with the increase of loading at high strain rate. The numerical results are consistent with change law of AE signals, AE signals are mainly in the pre-peak stage under uniaxial compression and AE signals are mainly in the peak stage under triaxial compression. The AE signal of coal specimens under low strain rate is more active than that of coal specimens under high strain rate.
Keywords
Coal;Confining pressure;Strain rate;Acoustic emission;Numerical simulation
Speaker
Ye LI
China University of Mining and Technology

Ye Li is currently a geotechnical engineering PhD candidate student in State Key Laboratory for Geomechanics and Deep Underground Engineering at China University of Mining and Technology. during her PhD study, she independently has hosted and completed the Jiangsu province postgraduate research and practice innovation project. She has been awarded a scholarship under the State Scholarship Fund to pursue in University College Cork of Ireland as s visiting PhD student. In recent years, her research focuses on the dynamic mechanical properties of rock under impact load, mechanism of crack propagation and failure of the rock. She has maintained this interest in application of finite element method to rock mechanics. And she has been successful to publish several papers in Theoretical and Applied Fracture Mechanics, Computers and Geotechnics etc.

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