Experimental Study on Mechanical and Acoustic Emission Characteristics of Rock Samples under Different Stress Paths

A series of tests on characteristics of acoustic emission have been performed on sandstone under uniaxial, conventional, and triaxial conditions and the unloading confining pressure path. The failure mode of rock specimen has been scanned by CT and a three-dimensional reconstruction was made. The di...

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Bibliographic Details
Main Authors: Tao Qin, Hongru Sun, Heng Liu, Junwen Zhang, Tao Li, Gang Liu, Zhenwen Liu
Format: Article
Language:English
Published: Hindawi Limited 2018-01-01
Series:Shock and Vibration
Online Access:http://dx.doi.org/10.1155/2018/4813724
Description
Summary:A series of tests on characteristics of acoustic emission have been performed on sandstone under uniaxial, conventional, and triaxial conditions and the unloading confining pressure path. The failure mode of rock specimen has been scanned by CT and a three-dimensional reconstruction was made. The differences on characteristics of AE, mechanics, and the failure mode of sandstone during the failure process under three paths are studied. The results show that the deformation of rock specimen is bigger, and axial strain and circumferential strain have a deformation platform at peak point of stress under the unloading confining pressure path. Characteristics of AE ringing are significantly affected by the confining pressure and stress path. AE ringing counts peak value, and accumulative ringing on the breaking moment as well as cumulative release energy is higher, which indicates that the rock failure is more violent under the unloading confining pressure path. The failure mode of rock specimen was dominated by shear failure under the conventional triaxial stress path. The tension failure is the main form at a lower initial value of unloading confining pressure, and the shear failure is more prominent at a higher initial value of unloading confining pressure.
ISSN:1070-9622
1875-9203