There are many mountainous areas in the southwest of Jiangxi Province. In order to save distance in the construction of national highways and high-speed railways, bridges and tunnels are often used to cross mountains and ravines. Part of 320 National Highway passes through this area. Bridge A is the largest bridge in this section. It has been running smoothly for 13 years since it was completed in 2003. Because of the huge traffic flow all the year round, the bearing capacity of bridge bearings is under great pressure. After testing, in order to ensure traffic safety, its bridge bearings need to be replaced. Similarly, in order to minimize the traffic impact, it is preliminarily decided to replace the bridge bearings without interrupting traffic. The climate is humid, rainy and hot in summer, and the lowest temperature in winter is minus 8. The bridge is a cast-in-place box girder highway bridge connecting two tunnels. A Bridge is a box of two rooms, divided into seven sections, the whole length of 150.6m.
Since 2015, maintenance workers have found serious shear damage in bridge rubber bearings, the internal steel plate is directly exposed to the outside, and there is serious corrosion and rust phenomenon. Experts are invited to check the design drawings. Many experts unanimously confirm that the main cause of severe shear damage to the bearing is the design defects. So an expert design group was set up specially to calculate and design the data provided by the design unit again and put forward new production parameters of the support.