Free rolling model of stone on expressway slope

In order to control rolling stone damage on expressway slope, a free rolling model of stone was built. The horizontal moving distance of stone was calculated while reaching the ground. Based on the energy conservation law, the impact energy of rolling stone to guardrail was deduced, and the reasonable way of protection was defined according to the energy. Computation result shows that the horizontal distance (2.156 m) is less than the distance between impact point and road curb (2.820 m), the impact energy is 132 kJ, so passive protecting mesh named AXI-015 (its protecting level is 150 kJ) can provide effective protection, and the model is feasible.