Buffering effect of gravel cushion layer on the impact of dry granular flow against a rock shed
SONG Yue1，2，JIANG Yuanjun1，WANG Meng1
(1. Institute of Mountain Hazards and Environment，Chinese Academy of Sciences，Chengdu，Sichuan 610041，China；
2. University of Chinese Academy of Sciences，Beijing 100049，China)
Abstract：Rock sheds are often used to protect the mountain roads from dry granular flow impact from landslides or avalanches. In order to further clarify the protective effect of cushion layer on rock shed，the impact mechanism of dry granular flow against rock shed and the cushioning effect of the cushion layer made of gravel were studied through the laboratory model experiment. The high speed camera recordings in the experiment showed that the gravel cushion layer deformed notably in the process of a dry granular flow impact. The force sensor measured the distribution of the impact force along the rock shed in the normal and tangential directions. The experimental results reveal that for the cases without a cushion layer，the maximum normal and tangential components of forces are close to the footing of the rock shed directly facing granular flow impact. With the addition of a cushion layer，the maximum impact force decreases and shifts approximately 30° to 45° away from the footing，indicating that the cushion layer can not only reduce the magnitude，but also change the mode of distribution of the impact force. It was found from the internal forces calculated that cushion layers can reduce the internal bending moment and internal shear force and increase the internal axial force，which enhances the safety of the rock shed. It was also verified that the finer granular material has higher capacity of energy dissipation. The experimental results fully indicated that a cushion layer played a significant role in buffering impact and dissipating energy in the process of a dry granular flow impacting on a rock shed.
宋 跃1，2，姜元俊1，王 萌1. 碎石垫层对碎屑流冲击棚洞的缓冲效应研究[J]. 岩石力学与工程学报, 2018, 37(10): 2359-2369.
SONG Yue1，2，JIANG Yuanjun1，WANG Meng1. Buffering effect of gravel cushion layer on the impact of dry granular flow against a rock shed. , 2018, 37(10): 2359-2369.
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2018, Vol. 37 
