Dynamic Response Analysis of Passive Flexible Protection System under Impact of Rockfalls
LI Huadong1,2, ZUO Mingyu1, LI Pu1,3, ZHAO Jinheng4
1. Institute of Technology，Sichuan Normal University，Chengdu 610101，China; 2. School of Civil Engineering and Environment，Xihua University，Chengdu 610039，China; 3. State Key Laboratory of Continental Dynamics，Northwest University，Xi’an 710069，China; 4. Electric Power Company Training Center of Sichuan Province，Chengdu 610072，China
Abstract：Finite element program ANSYS/LS-DYNA was applied to study the deformation and energy of passive flexible protection system under rockfalls impact. Using the ANSYS/LS-DYNA explicit analysis，dynamic responses of the passive flexible protection system to impact loads of rockfalls in different motion modes were simulated. According to the time history curves，the displacements，impact forces and energy change of rockfalls in different motion modes were contrasted. Results show that as the initial impact kinetic energy of rockfalls increases，the time required for the protective net to reach the maximum displacement decreases generally，and the impact time is between 0.11 s and 0.14 s. The maximum impact load of rockfalls occur at around 0.04−0.07 s，and increases with an increase in the initial kinetic energy. In the process of rockfall impact，energy dissipation occurs in the passive flexible protective structure，and the energy of steel wire mesh under rolling rocks is greater than that under bouncing rocks. Besides，the maximum peak energy of steel posts under rocks in the rolling state is greater than its counterpart under rocks in the bouncing state；the energy of steel posts increases sharply at the moment the steel wire mesh is broken under the impact of rolling rocks.
刘成清,陈林雅,陈驰,等. 落石冲击作用下被动柔性防护网整体结构试验[J]. 中国地质灾害与防治学报,2014,25(4): 37-44LIU Chengqing, CHEN Linya, CHEN Chi, et al. Integral structure test of passive flexible protective net under rockfall impact[J]. Chinese Journal of Geological Hazards and Prevention, 2014, 25(4): 37-44
[2]
YU Z X, ZHAO L, LIU Y P, et al. Studies on flexible rockfall barriers for failure modes,mechanisms and design strategies:a case study of western China[J]. Landslides, 2019, 16(2): 347-362
[3]
CHEUNG A K C, YIU J, LAM H W K, et al. Advanced numerical analysis of landslide debris mobility and barrier interaction[J]. HKIE Transactions, 2018, 25(2): 76-89
[4]
夏春兰. 被动柔性防护网在泥石流灾害治理中的应用研究[D]. 成都：西南交通大学, 2017.
[5]
WENDELER C, VOLKWEIN A, MCARDELL B W, et al. Load model for designing flexible steel barriers for debris flow mitigation[J]. Canadian Geotechnical Journal, 2019, 56(6): 893-910
[6]
SONG D, CHOI C E, ZHOU G G D. Geophysical flows impacting a flexible barrier:effects of solid-fluid interaction[J]. Landslides, 2017, 15(1): 99-110
[7]
ASHWOOD W., HUNGR O. Estimating total resisting force in flexible barrier impacted by a granular avalanche using physical and numerical modeling[J]. Canadian Geotechnical Journal, 2016, 53(10): 1700-1717
[8]
FERRERO A M, SEGALINI A, UMILI G. Experimental tests for the application of an analytical model for flexible debris flow barrier design[J]. Engineering Geology, 2015, 185: 33-42
[9]
SEGALINI A，BRIGHENTI R，UMILI G. A simplified analytical model for the design of flexible barriers against debris flows[C]//Landslide Science for a Safer Geoenvironment. [S.l.]： Springer International Publishing，2014： 725730
[10]
ALBRECHT V B，VOLKWEIN A. Numerical modelling of chain-link steel wire nets with discrete elements[J]. Canadian Geotechnical Journal，2019，56(3)： 398-419.
[11]
郭立平，余志祥，骆立茹，等. 基于力流等效的环形网顶破力学行为解析方法[J]. 工程力学，2019，30(1)： 1-12.GUO Liping，YU Zhixiang，LUO Liru，et al. An analytical method of puncture mechanical behavior of ring nets based on load path equivalent[J]. Engineering Mechanics，2019，30(1)： 1-12.
[12]
SONG D, ZHOU G G D, XU M, et al. Quantitative analysis of debris-flow flexible barrier capacity from momentum and energy perspectives[J]. Engineering Geology, 2019, 251: 893-910
[13]
TAN D Y, YIN J H, QIN J Q, et al. Large-scale physical modeling study on the interaction between rockfall and flexible barrier[J]. Landslides, 2018, 15(12): 2487-2497
[14]
KOO R C H, KWAN J S H, LAM C, et al. Dynamic response of flexible rockfall barriers under different loading geometries[J]. Landslides, 2016, 14(3): 905-916
[15]
齐欣，赵世春，韦韬，等. 防落石冲击柔性被动拦截网试验与数值分析[J]. 土木工程学报，2014，47（增刊2）： 62-68.QI Xin，ZHAO Shichun，WEI Tao，et al. Test study and numerical analysis of flexible protective structure for falling rocks[J]. Journal of Civil Engineering，2014，47(S2)： 62-68.
[16]
齐欣,余志祥,许浒,等. 被动柔性防护网结构的累计抗冲击性能研究[J]. 岩石力学与工程学报,2017,36(11): 2788-2797QI Xin, YU Zhixiang, XU Hu, et al. Study on the cumulative impact resistance of passive flexible protective net structure[J]. Chinese Journal of Rock Mechanics and Engineering, 2017, 36(11): 2788-2797
叶四桥,陈洪凯,许江. 落石运动模式与运动特征现场试验研究[J]. 土木建筑与环境工程,2011,33(2): 18-23,44YE Siqiao, CHEN Hongkai, XU Jiang. Field experimental study on the motion pattern and characteristics of rockfall[J]. Civil Architecture and Environmental Engineering, 2011, 33(2): 18-23,44
