Abstract: The prestressed reinforced soil structure was proposed to solve the problem of large-area depressions of soil highways under rockfall impacts in remote mountain areas. Comparative model tests for prestressed reinforced soil embankment and traditional soil embankment were conducted to explore the deformation performance, mechanical response, and load transmission mechanism of both embankments under rockfall impacts. The results show that the size of pits formed in prestressed reinforced soil embankment is significantly smaller than that in traditional soil embankment, which reflects the good impact deformation resistance of prestressed reinforced soil embankment. The embankment stiffness increases with the increase of impact times, resulting in the change of the time history of impact- induced additional stress in the embankment from “parabolic single peak” to “double peak”, and the “double peak” in the prestressed reinforced soil embankment occurs earlier than that in the traditional soil embankment. The duration of rockfall impact on the prestressed reinforced soil embankment is less than that on the traditional soil embankment, and the distribution of the impact on the prestressed reinforced soil embankment is more uniform, indicating that the prestressed reinforced soil embankment is more conducive to the impact diffusion. In addition, the internal impact load transmission ratio for prestressed reinforced soil embankment increases first and then decreases with the increase of impact times, which is consistent with the deformation law of reinforcement structure. The pit sizes corresponding to various impact times are predicted by the Levenberg-Marquardt optimization algorithm, which can provide reference for the engineering application of prestressed reinforced soil embankment and early warning in collapse disaster prone areas.

Key words: rockfall impact, prestressed reinforced soil embankment, impact deformation, additional stress, impact duration, impact transmission ratio