In recent years, with the rapid development of large cities, the core concept of smart transportation has been orderly promoted in urban planning and construction. New information boards, cameras, traffic sign posts, traffic signal lights, etc. play a full role in urban public transport, such as correct guidance of traffic travel and parking guidance. Generally, these special equipment are hung on single column, double column, F pole, T pole, gantry and other frames. These traffic sign posts are generally made of Q235 steel and coated with anti-corrosion paint or hot-dip galvanizing. After many years of road operation, the steel pipe rods appear rust, local fracture and other diseases. Overturning of steel pipe members occurred in some areas, causing personnel and property losses. How to choose a reasonable warranty mode more economically and conveniently to thoroughly solve the disease of steel pipe members needs further research and do a good job in urban management details.

1. Overview of common diseases of traffic sign posts:

After years of exposure to the sun and rain, steel pipe members have various degrees of disease, such as deterioration of steel structure coating, corrosion of steel pipe member bolts, structural deformation, loose and missing bolts and rivets, cracks at weld and fatigue positions, structural stress breaking through the original design value, cracking of foundation concrete, cracking and damage of foundation concrete, out of limit verticality of columns, out of limit beam deflection, etc. [1]. These diseases affect the safety of road operation, and bring potential safety hazards to vehicles and pedestrians on elevated roads and ground roads. The diseases combed are as follows.

1) The anchor bolt surface of the traffic sign pole member foundation is rusted. 2) The concrete wrapped around the rod foundation is missing, cracked and damaged, and the foundation concrete is damaged.

3) The steel structure of the member is rusted. 4) The steel member of the bar member is deformed, and the diagonal brace weld between columns is cracked. 5) The foundation anchor bolt is loose and the spring gasket is missing.

6) The beam is rusted or broken. 7) The column is rusted or broken. 8) The beam deflection and column verticality do not meet the specification requirements.

2 Maintenance plan for traffic sign posts

2.1 Maintenance principle