带开孔板连接件的压型钢板‒混凝土组合桥面板疲劳性能试验研究

Experimental Study of the Fatigue Behavior of Profiled Steel Sheeting-Concrete Composite Bridge Decks with Perfobond Connectors

摘要:

为研究带开孔板连接件（PBL连接件）的压型钢板?混凝土组合桥面板的疲劳性能，设计制作了1块连续组合桥面板试件，试件长9.25 m，宽1.5 m，最大混凝土板厚24 cm，压型钢板厚3 mm；开展了单点变幅疲劳加载和间隔性的静力加载试验，测试了试件的跨中挠度、钢底板和负弯矩区钢筋应变，观测了负弯矩区混凝土裂缝的分布与发展，测量了最大裂缝宽度，得到了组合桥面板试件受力性能随疲劳加载次数增加而退化的过程以及和试件的疲劳破坏形态。试验结果表明：组合桥面板试件的受力性能随着疲劳加载次数的增加而发生退化；在经过累计600万次疲劳加载后试件未发生破坏，表明其具有较好的抗疲劳性能；组合桥面板试件最终的疲劳破坏形态为跨中截面钢底板断裂破坏，裂纹最先萌生于PBL连接件与钢底板焊接位置，同时静载下负弯矩区混凝土的最大裂缝宽度达到了0.2 mm，利用线性损伤准则分析了已有的S-N（应力幅?循环次数）曲线对组合桥面板的适用性。

Abstract:

A continuous profiled steel sheeting-concrete composite bridge deck specimen with perfobond（PBL） connectors was tested to study the mechanical behavior at variable amplitude fatigue load. The specimen is 9.25 m long and 1.5 m wide， the thickness of the profiled steel sheeting is 3 mm， and the depth of concrete is 24 cm. The mid-span deflection， the strain of concrete and reinforcement， and the distribution of cracks and crack widths at the hogging moment region， as well as the procedure of the degeneration of stiffness and the fatigue failure mode were obtained and discussed. The test results show that the mechanical behavior of the composite deck specimen deteriorats with the increase in the fatigue loading times. The specimen does not fail at a fatigue loading of 600×10⁴ times， which shows that the composite deck has a high fatigue strength. The fatigue failure mode of the specimen is the steel sheeting crack at the mid-span， and the fatigue crack initiats at the welding part of the PBL connectors and steel sheeting. Meanwhile， the maximum crack width of concrete at the hogging moment region reaches 0.2 mm at static load. The applicability of the existing S-N curve to the composite deck was analyzed by using the linear damage accumulation rule.