钢-UHPC组合桥面移动车辆加载试验研究

随着公路交通运输的发展,车辆荷载不断提高,导致钢桥面板疲劳问题日益突出,尤其是对桥面系安全使用危害很大的顶板疲劳开裂问题。采用超高性能混凝土(UHPC)形成钢-UHPC组合桥面,因有望解决该类疲劳问题而成为近年来的研究热点。以武汉军山大桥改造工程为背景,利用工程现场的运输卡车,开展了钢-UHPC组合桥面移动车辆加载试验研究。试验结果表明:顶板与U肋连接处疲劳细节控制测点应力幅约为改造前的1/4~1/10,U肋与横隔板连接处疲劳细节DPS01.1控制测点应力幅约为改造前的1/10;疲劳细节C.6多轴疲劳效应显著,疲劳细节C.6.1控制测点应力幅约改造前的26%~29%;其余疲劳细节控制测点应力幅普遍约为改造前的1/2,U肋嵌补段疲劳细节UU01控制测点应力幅约为改造前的1/2。若大桥原钢桥面板抗疲劳设计寿命按5年计,则改造后有望解决其顶板疲劳开裂问题。

Experimental Study of Steel-UHPC Composite Deck on Moving Vehicle Loading

With the development of highway transportation,the continuous improvement of vehicle load and the limitation of design and construction level in the past,the fatigue problem of steel bridge deck is becoming increasingly prominent,especially the fatigue problem at the deck-to-rib joint which is harmful to the safe performance of bridge deck system.The steel-UHPC composite deck formed by UHPC is expected to solve this kind of fatigue problem and has become a research hotspot in recent years.In this paper,based on the reconstruction project of Wuhan Junshan Bridge,using the transportation trucks in the project site,the experimental research of steel UHPC composite deck on moving vehicle loading is carried out.The study results show that the control points stress amplitude of fatigue detail at the deck plate-U-rib weld joints are about 1/4~1/10 of that before the reconstruction;the control point stress amplitude of fatigue detail DPS01.1 at the U-rib-diaphragm weld joints is about 1/10 of that before the reconstruction,the multiaxial fatigue effect of fatigue detail C.6 is very remarkable,the control point stress amplitude of fatigue detail C.6.1 is about 26%~29% of that before the reconstruction,the control point stress amplitude of other fatigue details is around 1/2 of that before the reconstruction;the control point stress amplitude of fatigue detail at the U-rib butt weld joints is approximately 1/2 of that before the reconstruction.If the fatigue design life of the original steel deck of the bridge is 5 years,the deck plate fatigue cracking problem would be solved hopefully after the reconstruction.