桥梁损伤安全评定与维护管理策略

Damage safety assessment and maintenance management strategy of bridges

既有桥梁总会存在着不同程度的结构累积损伤 ,这不但影响桥梁的正常运营 ,而且会危及结构的使用安全。常规桥梁承载能力试验与新近发展起来的健康监测技术都很难独自对会导致桥梁脆性破坏的损伤累积进行有效检测。因此 ,提出基于损伤机理的结构损伤安全评定方法的设想 ,采用局部无损探测和整体、长期健康监测相结合的损伤判断、定位技术 ,在正确诊断桥梁损伤基础上 ,综合应用基于损伤力学、疲劳断裂、可靠度理论等多种方法和理论进行损伤安全评定。根据实时安全评定结果 ,按照不同桥梁结构的损伤特点 ,即时给出桥梁维护管理对策 ,以便桥梁管理部门采取相应措施保障桥梁安全使用。以上海市外白渡桥为例简要介绍该方法的实际应用成果 。

Damage cumulation in existing bridges affects not only on normal service of bridges, but also on service safety of structures. Both load carrying capacity testing and health monitoring technology could not alone identify damage cumulation, which often leads to brittle fracture of bridges. A new approach of damage safety assessment based on damage mechanism is proposed, which combines local nondestructive inspection with global health monitoring technology to identify and localize damage. On the basis of accurate damage identification, damage mechanics, fatigue and fracture mechanics, reliability theory are applied for damage safety assessment. According to the online safety assessment results and the damage characteristics of different types of bridges, maintenance management strategy is timely suggested in order to help management department to ensure the service safety of bridges. The practice application of the new method is introduced through the example of Waibaidu Bridge in Shanghai. Finally, some suggestions about damage safety assessment of bridges in the future are given.3 tabs,1 fig,14 refs.