Expert: The main cause of overturning of Wuxi viaduct is the construction of overloaded double-column pier structure.

 Expert: The main cause of overturning of Wuxi viaduct is the construction of overloaded double-column pier structure.

Modern Express News 12 pm, bridge expert, Wuxi Road and Bridge Chief Engineer Zhang Mingqing received an interview with reporters, according to his understanding at the scene, the main cause of the accident is the overload of large trucks, and is a serious overload.

Regarding the bridge structure, he said that there were doubts on the Internet about the design of single-column piers, which led to the relatively easy overturning of bridges. He believed that single-column pier viaducts had been adopted since the 1990s and had been widely used in high-speed applications. Essentially, as long as the operation is standardized, there will be no problems. In addition, the bridge belongs to the pre-stressed continuous box girder structure, because there are many overloads at present, many of these bridges in China have cracks, which need to be treated and strengthened. But as far as the accident is concerned, two overloaded trucks are not pulled apart. They are running close to each other on the same side of the road, which may form a certain frequency resonance.

Seriously overloaded vehicles are prone to rollover of single-column pier bridges

At that time, Zhang Mingqing introduced that it was very difficult to deal with the scene in a short time. First of all, the principle was to rescue people and rescue vehicles. At first, to open holes in the beams, it was necessary to knock down the overlay of the bridge deck and the floor, which took time. It is very difficult to drill holes by blasting because the section is small and the space is small. Consideration should also be given to the impact of blasting on the safety of adjacent side spans. As for the cutting scheme, when cutting, the force will be changed, and support is needed. The weight of the overturned bridge deck is 85 meters, and the weight of 1,5600 tons. Seventy-eight segments should be cut. So finally, the crushing scheme was adopted.

According to reports, crushers can be arranged on both sides of the bridge deck for in-situ crushing, with a total of twelve. Soil cushion is arranged under the beam to prevent the bridge deck from sliding.

For the future renovation plan, Zhang Mingqing believes that it is better to change to double-column pier, which does not have unbalanced force.

Source: Responsible Editor of Modern Express: Zhang Xianchao_NN9310