Study on fatigue damages and retrofit methods of steel box girder in a suspension bridge
Chen Zhuoyi1 Li Chuanxi1 Ke Lu1 Liu Yongming1,2 Lin Jiqiao3
1. Key Laboratory of Department of Education and Hunan Province, Changsha University of Science & Technology, Changsha 410114, China
2. Arizona State University, Tempe, AZ 85287, USA
3. Foshan Road & Bridge Construction Co., Ltd., Foshan 528000, China
Abstract：For orthotropic steel deck with flexible pavement, it is very difficult to overcome fatigue damages , and the fatigue cracks originating from the diaphragm around cope holes are mainly caused by out-of-plane deformation. A suspension bridge is used to investigate the information of structures size, vehicular loads and the fatigue damages. The diaphragm stresses under wheel loads and their related laws are analyzed, and the retrofit methods of diaphragm fatigue cracks are contrasted. The conclusions are as follows: (1) Reasonable structure and detail of orthotropic steel deck with flexible pavement can ensure its fatigue life cycle under normal vehicle loads. (2) Wheel load stresses in diaphragm around cope hole are mainly composed of in-plane stresses, the traditional conclusion that out-of-plane deformation basically result in fatigue cracks in this area is debatable. (3) The highest stress in the diaphragm around cope hole happens when the wheel locates at 0.3m apart from the concerned diaphragm longitudinally and right above the concerned sawtooth block horizontally. (4)The influence range of wheel load on stress around cope hole is 1.5 times that of diaphragm spacing, and is 2.0 times that of U rib spacing. (5) “Optimized cope hole” or “optimized cope hole combined with double-sided reinforcing steel plate” can be adopted as the retrofitting scheme for diaphragm fatigue cracking. Optimized notch shape and reinforcing steel plate shape can be unified for the entire bridge.
陈卓异 李传习 柯璐 刘永明 林继乔. 某悬索桥钢箱梁疲劳病害及处治方法研究[J]. 土木工程学报, 2017, 50(3): 91-100.
Chen Zhuoyi Li Chuanxi Ke Lu Liu Yongming Lin Jiqiao. Study on fatigue damages and retrofit methods of steel box girder in a suspension bridge. 土木工程学报, 2017, 50(3): 91-100.
