小铰缝空心板梁的预防性修复

Preventive Repair of Small Hinge Joint Hollow Slab Beams

摘要:

公路及城市桥梁中，中小跨径桥梁占比超过80%，其中大部分上部结构采用小铰缝空心板梁。随着桥梁老化和交通量的不断增加，铰缝病害日益严重，由于铰缝损伤造成的单梁受力已经威胁到桥梁安全。通过对多个工程进行跟踪调查后发现，铰缝损伤具有传导性，初始破坏的铰缝修复后，往往相邻的铰缝在短时间内会出现破坏，反过来又使得修复过的铰缝再度损伤，造成“屡修屡坏、越修越坏”。从预防性修复角度进行研究，提出除了对已破坏铰缝进行修复外，还要对“将坏未坏”的铰缝进行预防性修复，从而提高桥梁的安全性能，降低全生命周期内的维修费用。为提高修复效果，围绕铰缝的破坏机理、加固方法、加固材料、工程应用等方面，系统研究了空心板梁铰缝修复技术。

Abstract:

In highways and urban bridges, medium and small span bridges account for over 80%, in which the most of the superstructures are the small hinge joint hollow slab beams. With the aging of bridges and continuous increases of traffic volume, the disease of hinge joints is becoming increasingly serious. The single-beam stress caused by the damage of hinge joint has posed threats to bridge safety. Tracking investigations of multiple projects reveal that the damage of hinge joint is conductive. After the initial damaged hinge joints are repaired, the adjacent hinge joints often fail within a short period, which in turn causes the renewed damage to the repaired joints, resulting in a cycle of “repeated repairs with recurring failures, worsening with each repair”. From a preventive repair perspective, it is proposed that in addition to repairing already damaged hinge joints, the preventive repairs should also be conducted on hinge joints that are on the verge of failure so as to enhance the safety of bridge and reduce the maintenance costs over the full life cycle. To improve the repair effect, the systematic research is conducted on hollow slab beam hinge joint repair technologies by focusing on failure mechanisms, reinforcement methods, strengthening materials and engineering applications of hinge joints.