Analysis of rock burst ejection behavior and stress-energy response of coal under true triaxial loading-unloading conditions
Wen-tao Xu , Yun-hai Cheng , Wen-song Xu , Cheng Pan
Journal of Central South University ›› : 1 -22.
In order to explore the ejection failure mechanism and energy variation law of the in-focused energy rock burst and the concentrated stress rock burst. Based on the true triaxial disturbance unloading rock test system, high-stress unloading and different second principal stress loading tests were conducted. The mechanical properties and AE characteristics of coal samples under high-stress unloading and varying secondary principal stress loading conditions have been systematically analyzed. The area of the loading and unloading curve calculates the energy of the loaded coal sample. The elastic energy and dissipation energy ratio, the pre-peak energy and post-peak energy ratio, and the dissipation energy and elastic energy ratio are used to characterize the energy accumulation, dissipation, and release behavior. The energy mutation mechanism of coal samples under different loading and unloading conditions is revealed. The results indicate that the ejection failure characteristics exhibit the characteristics of tension-shear composite failure, in which tension failure is an inevitable occurrence during the ejection failure process. Unloading is more sensitive to energy accumulation ejection failure, and the ejection failure phenomenon tends to become more evident as the unloading degree deepens. The second principal stress has a great influence on the ejection failure of stress concentration rock burst, and the intensity of ejection failure increases with the increase of the second principal stress. The energy variation law of coal samples under high stress unloading and different second principal stress loading conditions is similar. With the increase in coal sample strength, the kinetic energy, impact tendency, and ejection failure probability of coal sample ejection fragments will also increase. The more fully damaged after unloading, the more prone to ejection. The evolution characteristics of AE have three stages, such as rising period, quiet period and destruction, in which the local ejection phenomenon appears in the destruction stage. The research method is certain rationality for the analysis of the energy evolution mechanism of coal rock. The research results provide an experimental basis for the ejection failure of rock burst. To provide support for targeted classified control measures.
deep coal mass / true triaxial / different principal stresses / unloading / rock burst
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| [2] |
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| [3] |
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| [4] |
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| [5] |
|
| [6] |
|
| [7] |
|
| [8] |
|
| [9] |
|
| [10] |
|
| [11] |
|
| [12] |
|
| [13] |
|
| [14] |
|
| [15] |
|
| [16] |
|
| [17] |
|
| [18] |
|
| [19] |
|
| [20] |
|
| [21] |
|
| [22] |
|
| [23] |
|
| [24] |
|
| [25] |
|
| [26] |
|
| [27] |
|
| [28] |
|
| [29] |
|
| [30] |
|
| [31] |
|
| [32] |
|
| [33] |
|
| [34] |
|
| [35] |
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Central South University
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