Abstract: A kind of light-type composite bridge deck system composed with steel and ultra-thin UHPC (Ultra-High Performance Concrete) layer was proposed. The proposed composite bridge deck not only could be used in deck structure whose pavement was thin, but also could reduce the risk of fatigue cracking of orthotropic steel deck and avoid the damage of asphalt pavement. Taking a certain large-scaled bridge as an engineering background, its performance was studied from FEM analysis and experiment. The results show that the 35 mm UHPC layer significantly improves the performance of the orthotropic steel deck, the fatigue stress-range of the top deck plate reaches a decline of 68.72% and the trough rib and transverse rib reach a decline ranging from 14.74% to 34.11%. The 35 mm UHPC layer can significantly reduce the risk of fatigue cracking of the deck. The transverse cracking strength of the UHPC layer obtained form the experiment is close to 26.3 MPa, and it is bigger than the maximum stress value 7.36 MPa produced by vehicle load with finite element method, which proves the feasibility of the proposed composite bridge deck system.

Key words: bridge engineering, ultra-thin UHPC layer, stress analysis, light-type composite bridge deck, orthotropic steel plate

摘要： 提出一种钢-超薄UHPC（Ultra-High Performance Concrete）层轻型组合桥面，既使得该组合桥面能运用于铺装层较薄的桥面结构，又降低了正交异性钢桥面的疲劳开裂风险，避免了 沥青铺装的病害问题。以某大桥为工程背景，从有限元分析和试验两方面对此结构的性能进行研究。结果表明：35 mm UHPC层对正交异性钢桥面板受力性能改善明显，顶板应力幅下降达到 68.72%，U肋和横隔板接近14.74%～34.11%，可大大降低钢桥面板疲劳开裂风险。试验得出的UHPC层横桥向开裂强度26.3 MPa，大于有限元计算下车辆荷载作用产生的最大应力7.36 MPa，证明 了此组合桥面结构的可行性。

关键词: 桥梁工程, 超薄UHPC层, 应力分析, 轻型组合桥面, 正交异性钢桥面