悬索桥主缆缠包带密封性能试验研究

Experimental Study of Sealing Performance of Main cable Wrapping Tape of Suspension Bridge

为优化大跨度悬索桥主缆新型"钢丝缠绕+缠包带热熔+空气除湿"三工艺复合防护体系的工程应用效果,以云南龙江特大桥为工程背景设计和制作了模拟实桥施工的复合体系主缆试验模型,测试不同加热时间、加热温度和空气压力的缠包带热熔性能,比较缠包带在不同压力和流量工况下的泄露率。试验结果表明:缠包带施工加热时间150~180s、加热温度120~130℃和空气压力4.5kPa为实桥最佳组合工艺参数,可以保证热熔后的缠包带具有良好的剥离强度性能;在合理的空气压力和流量条件下缠包带结构泄露率均小于5%,完全能满足实桥主缆防护施工指南和工艺规范的要求。

The protection system that combines the three techniques of steel wire binding, wrapping tape hot melting and air dehumidification is a new type for the long-span suspension bridge.To optimize the engineering application effect of the system, the Longjiang River Bridge in Yunnan Province was taken as the study background.A main cable testing model of composite system was designed and manufactured to simulate the construction of the real bridge, to inspect the hot melt performance of the wrapping tapes under different healing duration, healing temperatures and air pressures.The leakage rates of the wrapping tapes under different air pressure and flow were compared.The results of the testing indicate that the ideal technique parameters for the real bridge includes the heating time of 150~180 s, heating temperature of 120~130 ℃ and air pressure of 4.5 kPa, which can ensure that the wrapping tapes after hot melting have good shelling resistance.The leakage rate of the wrapping tape structure under the rational air pressure and flow is less than 5%, which can fully meet the requirements of the guidebook of protection construction for main cables of real bridge and the technique code.