Abstract:
In order to study the energy evolution characteristics of high concentration cemented backfill in coal mine, conventional triaxial compression tests of high-concentration cemented backfill under different confining pressures were carried out with the help of RTR-2000 triaxial dynamic test system for high pressure rocks.This paper analyzed the evolution law of the strain energy and the confining pressure effect during the deformation and failure of the specimens.The results show that: (1) for the specimen whose confining pressure is not 0, the ratio of dissipated strain energy corresponding to peak strength to absorbed strain energy is more than 70 %. Before the specimens reached the peak strength, they have undergone severe plastic deformation and failure.(2) in the process of deformation and failure of specimens, the absorbed strain energy increases rapidly, the elastic strain energy accumulates first and then releases, reaching the energy storage limit at peak strength, and the dissipated strain energy begins to increase rapidly from the stage of yield deformation.(3) under the condition of the same axial strain, the larger the confining pressure is, the larger the absorbed strain energy and elastic strain energy of the specimens are.The dissipated strain energy of the specimen with high confining pressure will exceed that of the specimen with low confining pressure as the axial strain increases.The confining pressure can greatly improve the stress level of the specimens, limit the radial deformation of the specimens, improve the energy storage capacity of the specimens, and restrain the deformation and failure of the specimens.