天津新港船闸桥锈蚀检测与结构性能评估

Corrosion Detection and Structural Evaluation of Lock Bridge at Tianjin Newport

锈蚀是危害沿海钢结构建筑物耐久性的主要因素之一,钢结构桥梁的锈蚀尤为严重.本文结合天津新港单叶式立转船闸桥,对其主要承载构件的锈蚀厚度进行了检测.基于检测数据,建立了船闸桥锈蚀前后的数值模型.分析了锈蚀前后结构主要力学指标的变化情况,结果表明:服役6年左右后,锈蚀已造成船闸桥承载能力显著降低,但结构承载力尚满足服役要求,不过安全储备有限.按平均锈蚀速度,如果现在按照规范进行防锈处理,预测该桥将于5年后耗尽安全储备.

Corrosion is one of the main risk factors of durability for coastal buildings with steel structure, especially for bridges with steel structure. In this paper, the corrosion thickness of main bearing components of the lock bridge at Tianjin Newport was detected, and the FEA models of the bridge were established based on the data with and with- out corrosion. The analysis of structural changes in the main mechanical indexes reveals that after 6 years of service, the corrosion significantly reduced the bearing capacity of the lock bridge. Although the bridge is still relatively safe at present, its safety reserve is limited. It is predicted that if the corrosion is cleaned in accordance with specifications, the bridge will run out of its safety reserve in 5 years at the average corrosion rate.