Coefficient of restitution of granular material at the seeper condition
CHEN Yulong1, ZHANG Ke2
1. State Key Laboratory of Hydroscience and Engineering, Tsinghua University, Beijing 100084, China; 2. Faculty of Electric Power Engineering, Kunming University of Science and Technology, Kunming 650500, China
Abstract：The motion of a rockfall is strongly dependent on the coefficient of restitution. This study investigates the coefficient of restitution in the presence of seeper. The coefficient of restitution was measured for various rockfall and seeper fall heights. The influences of the seeper depth and the fall height of the glass beads acting as the rockfall on the coefficient of restitution were investigated during normal impact on a flat steel wall with a seeper layer using free-fall experiments with a high-speed camera used to capture the collision mechanics. A collision model was then developed for the glass beads and the seeper on the rigid wall. The model took into account the viscous, surface tension, capillary, contact, drag, buoyancy and gravitational forces acting on the bead. The results show that the seeper significantly reduces the coefficient of restitution. Deeper seeper layers then dissipate more energy during the collisions that gives smaller coefficients of restitution. The coefficient of restitution increased with increasing bead fall height with part of the energy transferred from the glass bead to the seeper.
陈宇龙, 张科. 积水情况下颗粒材料碰撞恢复系数[J]. 清华大学学报（自然科学版）, 2018, 58(11): 986-991.
CHEN Yulong, ZHANG Ke. Coefficient of restitution of granular material at the seeper condition. Journal of Tsinghua University(Science and Technology), 2018, 58(11): 986-991.
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2018, Vol. 58 
