桥梁缆索雷击试验分析

桥梁的高大结构及其所处的地理位置决定了桥梁易遭受雷击的特点,缆索作为桥梁重要承重构件,一旦遭受雷击会影响桥梁的结构安全。对桥梁实际使用的缆索进行取样,在实验室内模拟雷击试验,通过5种试验模型分析雷击对桥梁缆索的影响,发现雷击将会造成高强度钢丝熔损。通过拉力试验分析缆索高强度钢丝遭受雷击前后抗拉强度的变化情况,发现其抗拉强度明显降低。通过冲击电压击穿试验计算缆索高密度聚乙烯护套的击穿强度,表明其无法承受自然界雷电的侵袭。试验分析表明,桥梁的缆索必须加强防雷保护。

Experimental Analysis of Lightning Stroke Test on Bridge Cable

Because of the tall structure and special position, bridge is vulnerable to lightning stroke. Once the cable as an important bearing member suffering the lightning stroke, the structural safety of the bridge will be affected. The in- fluences of lightning stroke on bridge cable was analysed through five experimental models of simulation experiment of lightning stroke in laboratory used by the real bridge cable samples. The experimental results shows that lightning stroke can cause high-tensile steel wires melting loss. The results of tension test was shown the tensile strength of high strength wire is reduced significantly after the lightning stroke. The breakdown strength of high density polyethylene sheath was calculated through impulse voltage breakdown test, the result shows that the high density polyethylene sheath can not endure the lightning stroke in nature. Experimental analysis indicates that the lightning protection of the bridge cable must be strengthened.