Sandstone energy and pore evolution under triaxial cycle loading and unloading conditions
[Objective]In order to provide guidance for the evolution of geotechnical engineering damage characteristics and sta-bility reinforcement under the complex stress environment.[Methods]The cyclic addition and unloading test of the sandstone was conducted,and the sandstone energy and pore evolution law were studied based on the macroscopic triaxial compression test and the microscopic NMR test.[Results]The result show that the partial stress-strain curve,the peak strength and the circumference pressure are positively correlated,and the test failure increases with the increase of the initial circumference pressure.Based on the energy density criterion,the radial energy shows a similar variation pattern.The energy dissipation increases significantly in the last stage,and the gap between the radial total energy and the radial elastic strain energy of the T2 spectrum of the specimen is larger.[Conclusion]The following conclusion are drawn:from the limit of the hysteresis ring and the energy density criterion,the energy loss characteristics of the rock and the destruction of the rock;from the microscopic nuclear magnetic resonance ima-ging combined with the analysis of the peak strength of the specimen.
万方数据
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