韧性挑篷防护网系统抗冲击性能研究  

Study on impact resistance of a resilient steel canopy protection system

作　　者：余志祥[1,2,3] 张丽君 骆丽茹[1,3] 金云涛 赵雷 齐欣[1,3] 赵世春[1,2,3] YU Zhixiang;ZHANG Lijun;LUO Liru;JIN Yuntao;ZHAO Lei;QI Xin;ZHAO Shichun(School of Civil Engineering,Southwest Jiaotong University,Chengdu,Sichuan 610031,China;National Engineering Laboratory for Prevention and Control of Geological Disasters in Land Transportation,Southwest Jiaotong University,Chengdu,Sichuan 610031,China;Research Center for Protection Structures Against Natural Hazards,Southwest Jiaotong University,Chengdu,Sichuan 610031,China)

机构地区：[1]西南交通大学土木工程学院,四川成都610031 [2]西南交通大学陆地交通地质灾害防治技术国家工程实验室,四川成都610031 [3]西南交通大学防护结构研究中心,四川成都610031

出　　处：《岩石力学与工程学报》2020年第12期2505-2516,共12页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家重点研发计划(2018YFC1505405);国家自然科学基金资助项目(51678504);四川省重点研发项目(2019YFG0001)。

摘　　要：为了提升艰险山区道路的落石防护韧性,提出一种可用于山区道路落石防护的韧性挑篷防护网系统。分析防护系统阻尼与韧性的相关性,建立柔性防护挑篷的落石抛出控制方法及冲击力计算方法,据此构建防护系统机制模型。设计三联足尺模型,基于大型落锤冲击试验台开展能量为150和500 kJ的冲击试验,通过高速摄相机、动态数据采集仪进行试验数据采集,分析试验模型的主要冲击动力响应特征。建立动力非线性力学模型,开展扩展参数的显式动力分析,全面地研究系统冲击动力响应。研究发现,系统冲击响应具有大变形张紧、回弹、自恢复三阶段特征;按提出的方法,可控制落石抛出,降低系统损伤;经测量,系统残余变形为初始垂度的9.3%~16.8%,显著低于既有柔性防护结构,表现出良好的韧性;与赫兹碰撞理论解析解相比,防护系统的试验冲击力降幅达99%;提出考虑缓冲大变形影响的冲击力计算方法,计算结果与试验或数值模拟结果相比,误差不超过6%。To improve the resilience of the rockfall protection system in remote mountain areas,a resilient steel canopy structure was proposed for rockfall protection in this paper.The correlation between system damping and resilience was analyzed,and a rockfall trajectory control model and an evaluation method of the impact force were established.Consequently,a mechanism model of the resilient steel canopy protection system was constructed.A full-scale impact test model composed of three units was conducted,and impact tests were carried out with impact energy of 150 and 500 kJ based on a large-scale impact test platform.The test data were collected by a high-speed camera and a dynamic data acquisition instrument,and the impact responses were analyzed.A dynamic nonlinear model was established,and the explicit dynamic analysis was carried out.The study shows that the impact response roughly experiences three stages such as large deflection with high tension,spring back and system recovery.According to the design method proposed in this paper,rocks’throwing out is controllable and the damage of the system can be reduced.The residual deflection of the net is 9.3%–16.8%of the initial deflection,which is significantly lower than the existing flexible protection system,showing very strong resilience.Compared to the analytical solution of the Hertz collision theory,the impact force is reduced by 99%.A calculation method for the impact force was proposed considering the influence of large deflection,and the errors are less than 6%compared with the test results.

关 键 词：工程地质 落石 棚洞 韧性结构 冲击与防护 足尺试验 

分 类 号：P32[天文地球—地球物理学]