文献类型：期刊文献

英文题名：Occurrence conditions of the reverse rotation of rockfall and its influence on the restitution coefficient

作者：Ji, Zhong-Min[1,2,3];Wang, Ting-Hui[2];Wu, Fa-Quan[1];Wang, Dong-Po[1];Li, Zhen-Hua[4]

机构：[1]Shaoxing Univ, Sch Civil Engn, Shaoxing, Peoples R China;[2]Henan Polytech Univ, Sch Civil Engn, Jiaozuo, Peoples R China;[3]Chengdu Univ Technol, Key Lab Geohazard Prevent & Geoenvironm Protect, Chengdu, Peoples R China;[4]Henan Polytech Univ, Sch Energy Sci & Engn, Jiaozuo, Peoples R China

年份：2023

卷号：11

外文期刊名：FRONTIERS IN EARTH SCIENCE

收录：SCI-EXPANDED(收录号：WOS:001068151400001)、、Scopus(收录号：2-s2.0-85171856781)、WOS

基金：The authors declare financial support was received for the research, authorship, and/or publication of this article. This work was financially supported by the National Natural Science Foundation of China (No. U2244228; No. 42307250; No. 41831290), Opening fund of State Key Laboratory of Geohazard Prevention and Geoenvironment Protection (Chengdu University of Technology) (Grant No. SKLGP2023K007), China Postdoctoral Science Foundation (No. 2022M721033) and Natural Science Foundation of Henan (No. 222300420366).

语种：英文

外文关键词：influencing mechanism; rockfall; impact coefficient; restitution coefficient; reverse rotation

外文摘要：When rockfall occurs along dense rock slopes, the rotation direction of rockfall is not always downhill. Specifically, the rockfall may obtain a reverse rotation speed (RRS) after impact under certain conditions, the effect of which on the restitution coefficient (RC) cannot be ignored. According to the statistical results of the reverse rotation (RR) phenomena of blocks obtained from previous experiments, the occurrence of RR is correlated to the block shape, incident angle, and contact attitude. In this study, considering a typically shaped cubic block, the critical condition for the RR is preliminarily deduced. Based on the results, the influence of the RRS on the RC for four typically shaped blocks is examined using a customized device. Results show that the tangential RC (Rt) values of each block are not sensitive to the change in the RRS, the distribution is relatively concentrated and the values are high. Moreover, the normal RC (Rn) values are not sensitive to the RRS, and the distribution is relatively discrete. The RRS influences Rn; however, it is difficult to directly establish the relationship between them. To this end, considering the contact attitude and shape of the block, an integral variable, the impact coefficient (Ic), is proposed to determine the influence of RRS on Rn. Moreover, the impact-bounce behaviours of the block are categorized and analysed. For the block rebound following a single impact, Ic and Rn are positively and negatively correlated when the mass centre of the block (MC) is in front and behind the contact point (CP), respectively. For the block rebound following two successive impacts, with the increase in Ic, the Rn increases. These conclusions help clarify the mechanism of the influence of the RRS on RC and provide vital information and ideas for the development and optimization of a program to accurately predict rockfall trajectories.