新型正交异性钢-混组合桥面板足尺模型疲劳试验

摘要

为改善新型正交异性钢混组合钢桥面疲劳性能,采用理论推导、有限元模拟和足尺模型疲劳试验对其纵肋腹板与横隔板焊接细节进行研究.首先将由大尺寸纵肋组成的正交异性组合桥面系简化成铰接的双纵肋计算模型,然后进行足尺模型疲劳试验,分析混凝土层和钢桥面构造受力及开裂情况.结果表明:理论模型能较好反映纵肋实际力学行为;铺设混凝土层后,桥面板焊接构造细节疲劳应力得到很大改善.所提出的新型正交异性钢混组合钢桥面可作为解决正交异性钢桥面疲劳开裂问题的一种新思路.%In order to improve the fatigue performance of new-type steel-concrete composite orthotropic deck, fatigue test and numerical investigation were conducted to evaluate the fatigue performance of its rib-to-crossbeam welded joints. First of all, a double-rib theoretical model joined with hinges was presented to analyze shear behavior of large size rib due to torsion and bending of orthotropic deck. Then the stress and cracking in the concrete slab and steel details were measured and analyzed in the full-scale specimen. The theoretical results showed a good correlation with the observed stress results. The test results indicated that the fatigue stress of rib-to-deck joints decreased significantly with overlaying concrete, namely the risk of fatigue cracking reduces. The proposed composite orthotropic deck is recommended as a new solution to the steel deck cracking.