Experimental study on fragmentation effects of rockfall impact upon slope
LU Qing1，ZHOU Chunfeng1，YU Yang2，XIAO Zhipeng1，ZHENG Jun1
(1. College of Civil Engineering and Architecture，Zhejiang University，Hangzhou，Zhejiang 310058，China； 2. Ocean College，Zhejiang University，Zhoushan，Zhejiang 316021，China)
A series of indoor impact tests were carried out by a self-developed rockfall impact testing system. The coupled effects of different factors，such as the rockfall mechanical property，the impact velocity，the incidence angle and the sample size，on the rockfall impact fragmentation mechanism and the rockfall trajectory characteristics were fully investigated. The results show that the mechanical property and the impact velocity are the two major factors that determine the rockfall fragmentation during the impact upon the slope surface. The fragmentation degree of rockfall increases with the growth of impact velocity while decreases with the improvement of rockfall mechanical property. Moreover，there is a normal velocity threshold beyond which the rockfall fragmentation occurs. The threshold decreases with the deterioration of rockfall mechanical property. Furthermore，the impact incidence angle will greatly influence both the rockfall fragmentation and the energy restitution coefficient. Fragmentation of rockfall due to the impact will not only slightly decrease the energy restitution coefficient but will also increase the velocity of some fragments, which may lead to adverse effects on the protective structure.
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2017, Vol. 36 
