  An asteroid spun up to its critical limit has unique surface mechanical
properties that its gravity and the centrifugal force largely balance, creating
a relaxation environment where low-energy events such as mass shedding may
trigger subsequent long complex motion of an asteroid's regolith grains.
Exploring such an evolution process may provide key clues for understanding the
early formation of multi-asteroid systems. This paper investigates the complex
evolution process of loose particles becoming triggered by shedding events and
the dependency of their dynamical propagation on the contact mechanical
properties of the asteroid surface. We present a numerical model for tracking
the trajectory of a shed particle that considers the collision between the
particle and the surface of an asteroid. Monte Carlo simulations are performed
to reflect the statistical behavior of shed particles. We also introduce
zero-velocity surfaces to our data-based analysis in order to reveal the
intrinsic invariance of the evolutionary processes. We used the average
mechanical energy of the particle cloud to check the connection between contact
property and the temporal-spatial distribution of the shed particles. We sketch
a common evolutionary path of the particle in the vicinity of a fast-rotating
asteroid, that is, particles dislodged from the unstable region will eventually
enter, through several collisions with the surface, non-return orbits that
launch from the minimum geopotential area of the unstable region. The common
trend is independent of any particular asteroid morphology, and all shed
particles enter the same evolutionary path. We also find that the orbital
energy of the particle cloud is statistically independent of the surface
contact property, meaning that the collision coefficient of restitution is a
nonsensitive parameter in the outward spreading process of the shed particles.
