落石在棚洞垫层上的运动轨迹研究

落石运动形式包括平抛运动、碰撞运动、斜上抛运动以及滚动运动。根据Hertz的弹性碰撞理论以及Beta函数，分析了落石在垫层上的运动轨迹和落石冲入垫层的深度以及最大冲击力。考虑落石在垫层上的滚动摩擦，忽略落石与垫层之间的滑动摩擦，得出落石在垫层上的滚动距离。根据弹跳运动的计算，护栏高度必须大于落实弹跳高度H2，才能保证行车的安全性。

Study on Movement Trace of Falling Rocks on Tunnel Shed Cushion

The rocks’ motion forms included horizontal projectile motion, collision, up-inclined projectile and rolling motions. According to Hertz’s elastic collision theory and Beta function, The movement trace of falling rocks on cushion,both the depth of the rocks rushing into the cushion and the maximum impact force resulted were analyzed. With the rolling friction of the falling rocks on the cushion taken into consideration, and the sliding friction between the falling rocks and the cushion ignored, the rolling distance of the falling rocks on the cushion was found out. It is concluded that, on the basis of jumping movement calculation, the guardrail height must be greater than the jumping height H2, in order to ensure driving safety.