| Abstrakt: |
In this paper, based on the experimental result of closed fractured rock, combined with the results of nuclear magnetic resonance, the variation of porosity before and after the test of closed fractured rock is compared and analyzed. At the same time, the numerical model of closed fractured rock with different dip angles is established by using the Particle flow code, and the simulation results are compared with the experimental results. Finally, the numerical simulation method is used to analyze the rupture evolution process of closed fractured rock. The results show that: (1) When the inclination angle of the closed fracture changes from 0 to 90°, the peak stress and elastic modulus of the rock decrease first and then increase, showing a V-shaped trend. (2) The results of nuclear magnetic resonance test show that the macro and meso-pores are mainly developed in the rock during the test, and the micro-pores are the least developed. The peak stress and the porosity after compression decrease first and then increase with the increase of the fracture dip angle. (3) The simulation results of macroscopic mechanical parameters of closed fractured rock with different dip angles are very close to the experimental results, and the internal stress state of 0° and 90° closed fractured rock is similar to that of complete rock. For the 60° closed fractured rock, there is obvious stress concentration around the fracture. (4) By recording and calculating the crack proportion, it is found that the peak stress of the rock model is positively correlated with the crack proportion, indicating that the stronger the bearing capacity of the rock model, the more cracks generated, and the more serious the destruction degree of the rock model, which is consistent with the change law of porosity after compression. It is also proved that the crack proportion can be used as an important index to quantify the destruction degree of rock model. The above conclusions provide a theoretical basis for the analyze of the deformation and failure characteristics of fractured rock. The influence of closed fracture dip angle on the macroscopic mechanical parameter of rock is discussed, and the rupture evolution law of fractured rock under load is revealed. [ABSTRACT FROM AUTHOR] |
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