钢箱梁悬索桥大节段正交异性钢桥面板疲劳性能试验

Large sectional fatigue experiment of the orthotropic steel deck from a box-girder suspension bridge

针对正交异性钢桥面板的焊接细节在反复荷载作用下易疲劳开裂的问题,以三峡库区某大跨悬索桥的钢箱梁正交异性钢桥面板为工程背景,进行1∶2缩尺的钢桥面板疲劳性能试验研究,进行设计寿命期内的疲劳试验和极限寿命期内的疲劳试验.疲劳试验结果表明:200万次的循环加载后,模型上各测点的应力值波动很小,在加/卸载过程中位移具有良好的对称性、可恢复性与重复性,说明模型的应力状态稳定,没有出现因局部开裂、损伤而导致模型应力显著变化的现象,说明该桥的正交异性钢桥面板的构造满足设计要求,且有一定的安全储备.

Based on an orthotropic steel deck of a long-span suspension bridge in Three Gorges reservoir area, a 1 ： 2 scaled-down fatigue experiment in design life span and limit life span was carried out to explore the fatigue behavior of critical details in the steel orthotropic decks of steel box girder suspension bridge, which is sensitive to fatigue crack under repeated loads. The fatigue experiment results show that the stress fluctuation ranges of critical details of the fatigue model are very small after 2 million times of cyclic loading in design life span, displacements of measure points of the fatigue model have good symmetry and recoverability in the static loading and unloading process, and there are no local fatigue cracks and damage during the experimental process of the design life span. It is considered that the orthotropic steel deck of this experiment in good welding and normal maintenance will not appear cracking in the design life, and fatigue performance of the orthotropic steel deck meets the design requirements and has some safety reserve.