摘要
为了研究落石形状和尺寸对恢复系数的影响,通过专门设计的落石碰撞测试装置,分别展开10种不同形状和5种不同尺寸的试块与坡面的碰撞测试。基于冲击动力学理论对试验结果进行分析,法向恢复系数R_(n)对试块形状的变化非常敏感,且非棱角状试块的R_(n)值明显高于棱角状试块。非棱角状试块R_(n)值大小依次为球形>椭球>球底圆锥>圆柱>圆盘,棱角状试块的R_(n)值大小依次为正二十面体>正方体>正四面体>长方体>三角板。综合考虑试块的几何构型和表面积分布特征,引入一个新的形状量化指标——形状因子η,其与非棱角状试块和棱角状试块的R_(n)值分别呈强线性正相关。相较于R_(n),试块形状对切向恢复系数R_t的影响较弱,且棱角状试块的R_t值整体略大于非棱角试块。试块尺寸对R_(n)和R_t的影响均较为显著,且与R_(n)和R_t均呈良好的线性负相关关系。这些获得的规律可为落石灾害的准确预测提供重要参考。
In order to study the effect of rockfall shape and size on the coefficient of restitution(COR),ten test blocks with different typical shapes and five test blocks with different sizes were adopted to conduct rockfall impact tests by a specially designed device.Based on the impact dynamics theory,the analysis of test results show that the normal COR(R_(n))is very sensitive to the change of the block shape,and the R_(n)values of the non-angular shaped blocks are significantly higher than that of the angular shaped blocks.The R_(n)values of five non-angular shaped blocks are spherical>ellipsoid>cone with spherical base>cylinder>disk,and those of five angular shaped blocks are icosahedron>cube>tetrahedron>cuboid>triangle.Considering the geometric configuration and surface area distribution characteristics of the blocks,a new comprehensive shape quantification index-shape factor(η)is introduced,which has strong linear positive correlations with the R_(n)values of non-angular and angular shaped blocks respectively.Compared with R_(n),the effect of the block shape on the tangential COR(R_t)is relatively weak,and the overall R_t values of the angular shaped blocks are slightly larger than that of the non-angular shaped blocks.Moreover,the size of the block has a significant impact on R_(n)and R_t.There are good linear negative correlations between the test block size and R_(n)and R_t.The rules obtained in this study provide important references for accurate prediction of rockfall disasters.
作者
姬中民
唐一举
伍法权
刘静
陈天立
陈志坚
JI Zhong-min;TANG Yi-ju;WU Fa-quan;LIU Jing;CHEN Tian-li;CHEN Zhi-jian(School of Earth Science and Engineering,Hebei University of Engineering,Handan,Hebei 056038,China;College of Safety Science and Engineering,Henan Polytechnic University,Jiaozuo,Henan 454003,China;Department of Resources and Environment,Henan College of Industry&Information Technology,Jiaozuo,Henan 454003,China;School of Civil Engineering,Shaoxing University,Shaoxing,Zhejiang 312000,China;School of Earth Science and Engineering,Hohai University,Nanjing,Jiangsu 211100,China)
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2021年第3期665-672,共8页
Rock and Soil Mechanics
基金
江苏省政策引导类计划项目(No.BY2015002-05)。
关键词
落石
形状
尺寸
恢复系数
形状因子
rockfall
shape
size
coefficient of restitution
shape factor
