被动柔性防护网结构足尺冲击试验研究

Full Scale Experimental Testing of Flexible Rockfall Protective Structures

为研究被动柔性防护网结构的落石防护性能,设计2组防护能级为750 k J的柔性被动防护网结构,进行足尺冲击试验研究。模型1为按照现有标准所选型得到的系统配置;模型2为改进后的柔性被动防护网结构。试验结果表明:模型1无法拦截750 k J落石的冲击,系统崩溃;模型2成功地拦截了落石,且冲击后模型2的各主要组成构件等均未发生破坏,仅需要对耗能元件进行更换,即可继续投入使用。通过对高速视频的解构,对各部分组成构件的运动和受力特征进行详细分析,明确系统的三阶段工作历程,并分析系统失效的关键因素,同时,对实测的钢丝绳拉力时程进行对比分析。研究结果为今后柔性被动防护网结构的设计提供了理论基础。

In order to study the performance of flexible rockfall protective structure, two flexible protective structures of 750 kJ protective level are designed for full scale impact test. Model 1 is obtained in accordance with the existing standard;model 2 is the improved system. The test results show that: model 1 failed to intercept 750kJ rockfall impact and the system clasped;model 2 successfully intercepted rockfall, and all the major components remained complete with only consumables to be replaced for continuous service. Through the replay of high-speed video, the movement and stress of each part of the members are analyzed, the performances of a three-stage process of the system are identified, and key factors of system failure are analyzed. Meanwhile, the measured tension force of the steel wire in time-history is compared and anlyzed. The research results provide a theoretical basis for the future design of flexible rockfall protective structure.