scholarly journals Research on Multijoint Rock Failure Mechanism Based on Moment Tensor Theory

2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
J. F. Chai
Keyword(s):  
Acoustic Emission ◽  
Failure Mechanism ◽  
Moment Tensor ◽  
Spatial Location ◽  
Rock Failure ◽  
Particle Flow Code ◽  
Emission Data ◽  
Diagram Method ◽  
Tensor Theory ◽  
The Moment

To reveal the influence of the number and location of joints on rock failure mechanism, using Particle Flow Code (PFC) to simulate the calculation of a large amount of acoustic emission data generated during breeding, development, and penetration of rock cracks, the fracture parameters such as the spatial location, rupture azimuth, rupture type, stress state, and moment magnitude of acoustic emission events in various fracture stages of multijoint rock were studied based on the moment tensor theory, the P-T diagram method, and the T-k diagram method. It will be of great importance in the geotechnical engineering field.

scholarly journals Microscopic Failure Mechanism Analysis of Rock Under Dynamic Brazilian Test Based on Acoustic Emission and Moment Tensor Simulation

2021 ◽  
Vol 8 ◽  
Author(s):  
Zilong Zhou ◽  
Jing Zhou ◽  
Yuan Zhao ◽  
Lianjun Chen ◽  
Chongjin Li
Keyword(s):  
Acoustic Emission ◽  
Failure Mechanism ◽  
Failure Mode ◽  
Moment Tensor ◽  
Brazilian Test ◽  
Mechanism Analysis ◽  
Micro Cracks ◽  
Moment Tensor Analysis ◽  
Simulation Results ◽  
The Moment

The dynamic tensile failure of rock is a main failure mode in deep underground engineering projects. The microscopic failure mechanism analysis of this failure mode plays a key role in dynamic disaster warning. Moment tensor inversion is a very well-known method used to analyze failure mechanisms. However, an acoustic emission (AE) event cannot be accurately distinguished in rock dynamic experiments at the laboratory scale, because there are hundreds of AE events generated within a few hundred microseconds in one dynamic test. Therefore, moment tensor analysis is rarely applied in rock dynamic tests with laboratory scale. In this paper, AE and moment tensor simulations with the discrete element method (DEM) are introduced to analyze the microscopic failure mechanism of rock under a dynamic Brazilian test. Comparing the simulation results of AE and moment tensor analysis with the simulation results of micro-crack with DEM, the moment tensor discriminant method can obtain the mechanical mechanism and energy level of micro-cracks. Furthermore, R, which is the ratio of isotropic and deviatoric components of the moment tensor, is used to analyze the AE source mechanism. The implosion, shear, and tensile of the AE source mechanism can better explain the evolution process of main axial crack and the shear failure zones of the Brazilian disc specimen under dynamic tensile simulation. These findings contribute to a better understanding of the microscopic failure mechanism of rock under a dynamic tensile test than the statistical types of micro-cracks based on break bonds with DEM.

Microscopic acoustic emission simulation and fracture mechanism of cemented tailings backfill based on moment tensor theory

2021 ◽  
Vol 308 ◽  
pp. 125069
Author(s):  
Aiping Cheng ◽  
Pengfei Shu ◽  
Daiqiang Deng ◽  
Chengsong Zhou ◽  
Shibing Huang ◽  
...  
Keyword(s):  
Acoustic Emission ◽  
Fracture Mechanism ◽  
Moment Tensor ◽  
Tensor Theory

An Acoustic Emission Data-Driven Model to Simulate Rock Failure Process

2019 ◽  
Vol 53 (4) ◽  
pp. 1605-1621 ◽  
Author(s):  
Jiong Wei ◽  
Wancheng Zhu ◽  
Kai Guan ◽  
Jingren Zhou ◽  
Jae-Joon Song
Keyword(s):  
Acoustic Emission ◽  
Failure Process ◽  
Rock Failure ◽  
Data Driven ◽  
Emission Data ◽  
Rock Failure Process

scholarly journals Acoustic Emission Characteristics and Joint Nonlinear Mechanical Response of Rock Masses under Uniaxial Compression

Energies ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 200
Author(s):  
Zhongliang Feng ◽  
Xin Chen ◽  
Yu Fu ◽  
Shaoshuai Qing ◽  
Tongguan Xie
Keyword(s):  
Acoustic Emission ◽  
Uniaxial Compression ◽  
Inclination Angle ◽  
Failure Modes ◽  
Strain Curve ◽  
Particle Flow Code ◽  
Rock Masses ◽  
Physical Experiments ◽  
Inclination Angles ◽  
Joint Inclination

The joint arrangement in rock masses is the critical factor controlling the stability of rock structures in underground geotechnical engineering. In this study, the influence of the joint inclination angle on the mechanical behavior of jointed rock masses under uniaxial compression was investigated. Physical model laboratory experiments were conducted on jointed specimens with a single pre-existing flaw inclined at 0°, 30°, 45°, 60°, and 90° and on intact specimens. The acoustic emission (AE) signals were monitored during the loading process, which revealed that there is a correlation between the AE characteristics and the failure modes of the jointed specimens with different inclination angles. In addition, particle flow code (PFC) modeling was carried out to reproduce the phenomena observed in the physical experiments. According to the numerical results, the AE phenomenon was basically the same as that observed in the physical experiments. The response of the pre-existing joint mainly involved three stages: (I) the closing of the joint; (II) the strength mobilization of the joint; and (III) the reopening of the joint. Moreover, the response of the pre-existing joint was closely related to the joint’s inclination. As the joint inclination angle increased, the strength mobilization stage of the joint gradually shifted from the pre-peak stage of the stress–strain curve to the post-peak stage. In addition, the instantaneous drop in the average joint system aperture (aave) in the specimens with medium and high inclination angles corresponded to a rapid increase in the form of the pulse of the AE activity during the strength mobilization stage.

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