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摘要
Blasting is an essential part of open-pit mining, but the impact disturbance produced by continuous blasting operations will weaken the long-term stability of open-pit slopes. In order to study the influence of impact disturbance on the creep characteristics of rock, we prepared rock samples 150 mm × 75 mm × 75mm in size with the argillaceous shale from the weak interlayer, and carried out shear creep tests under different impact energy disturbances with the self-developed rock impact-shear creep test system. The following conclusions are drawn based on the test results: (1) The impact disturbance has a significant interference effect on the shear creep failure of soft rock. With the increase of impact disturbance energy, the accelerated creep duration and the total creep failure time of the soft rock are shortened, and the shear creep failure strength decreases. (2) The impact energy can affect the spread characteristics of the shear failure surface of rock samples. The impact disturbance energy destroys the rock sample structure, resulting in an increase in the number of shear cracks. (3) The total deformation of the rock sample is positively correlated with impact energy. With the increase of impact energy, the proportion of plastic deformation becomes larger and the proportion of elastic deformation becomes smaller. After applying a disturbance of impact energy of 7.09 J, the ratio of plastic deformation to total deformation is no less than 73.1%. According to the test results, a damage factor D based on impact energy is introduced, and a shear creep damage model of soft rock considering the impact disturbance effect is established. The Broyden-Fletcher-Goldfarb-Shanno (BFGS) algorithm and the 1stOpt mathematical software for general global optimization are used to identify model parameters. It is found that the established model can well describe the whole process of shale creep deformation under impact disturbance. This study provides a certain theoretical basis for the research on long-term stability of mine slope under blasting disturbance. ? 2022, Editorial Department Chinese Journal of Solid Mechanics. All right reserved.
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