新型半开口纵肋正交异性钢桥面板疲劳性能试验研究

Experimental Study of Fatigue Performance of Orthotropic Steel Bridge Deck with Semi-Open Longitudinal Ribs

为了改善常规正交异性钢桥面板的疲劳开裂问题,提出新型半开口纵肋正交异性钢桥面板结构,该结构通过在纵肋底部开口实现顶板与纵肋双面焊接,提高焊缝质量,降低纵肋与横隔板的刚度差。为验证该新型钢桥面板的疲劳性能,设计制作钢桥面板节段足尺模型进行疲劳试验,采用应力应变法、数字图像法、声发射法等技术监测应力和裂纹发展。结果表明:在1 000万次循环加载过程中,新型钢桥面板各构造细节处均未出现疲劳裂纹;与常规正交异性钢桥面板相比,新型钢桥面板纵肋与横隔板连接处的应力幅大幅降低;新型钢桥面板结构显著改善了正交异性钢桥面板的抗疲劳性能。

A new type of orthotropic steel bridge deck(OBD)structure was proposed in order to solve the fatigue cracking problems of conventional OBDs.In the structure,apertures are set at the bottom of the longitudinal ribs to realize double-sided welding of the deck plate and the longitudinal rib,so that,the quality of welding can be improved and the difference in stiffness between the longitudinal ribs and the diaphragm can be reduced.To verify the fatigue performance of the new OBD,a full-scale model of the steel bridge deck segment was designed and fabricated to carry out fatigue tests,and a variety of techniques including the stress-strain method,digital image method,and acoustic emission method were adopted to monitor stress and crack development.The results show that,during the 10 million cycles of loading,no fatigue cracks appear in the structural details of the new steel bridge deck.Compared with conventional OBDs,the stress amplitude at the rib-to-diaphragm joint of the new OBD is greatly reduced,and the new structure significantly improves the fatigue resistance of orthotropic steel bridge decks.