Pay attention to bridge safety! Many studies claim that there are hidden dangers in the safety of single-pier bridges

category:Finance
 Pay attention to bridge safety! Many studies claim that there are hidden dangers in the safety of single-pier bridges


According to the photos taken at the site of the accident, the overturning viaduct is suspected to be a single pier bridge structure.

Single-pier bridges have many advantages, such as beautiful form and small area, which make them occupy an important position in the construction of modern bridges.

At the 25th Annual Conference of Beijing Mechanics Association held at the beginning of this year, Peng Shikui and Luo Chuanyun, scholars of China University of mining and technology, submitted the paper Analysis on overturning stability of single pier bridge, which clearly stated that the lateral stability of single pier bridge is poor, and it is easy to cause overall overturning accident.

The first financial reporter noted that in some professional academic journals such as highways and bridges, there are many articles on the analysis of anti overturning stability of single pier bridges in recent years. Some experts say that in recent years, single pier bridge overturning accidents occur frequently, which has aroused great concern of engineering and technical personnel. Bridges in accidents did not find problems in the previous routine inspection and detection, which indicates that relying solely on routine inspection and detection can not effectively eliminate potential safety hazards, and needs further evaluation.

Experts said that due to the lack of design theory, in recent years, there have been a number of single-column pier-beam bridge body overturning accidents. When a heavy vehicle passes through a single pier bridge, it is easy to cause transverse overturning of the box girder superstructure. It is urgent to study the static analysis and reinforcement measures of this kind of bridge.

Wan Shicheng and Huang Qiao, academicians of the School of Communications of Southeast University, also wrote in China-Foreign Highway (No. 4, 2015), The torsional resistance of single-column piers is weak, and the overturning problem under the bias load of heavy vehicles is more prominent. The bridge overturning accident caused by this may cause significant loss of life and property. In China, the study of overturning of single-pier continuous girder bridges under eccentric loading is still in its infancy, and the computational theory, design method and relevant norms are not yet mature. There are few reports on the overturning of bridges under unbalanced loads, so there are few references for Chinese scholars.

It is found that single pier linear girder bridge and curved girder bridge with large curvature radius are prone to bearing void and even structural overturning accidents. In addition, in the case of serious overload of single-column Pier-Girder bridge, the possibility of bearing void or even overturning damage of superstructure will be greatly increased.

Xu Hanzheng, associate professor of Bridge Department of Highway College of Changan University, has previously told the media that single-column pier continuous cast-in-place box girder structure is widely used in urban interchanges and ramps in China. The advantages of this design are to reduce the area occupied, improve the layout of the lower mechanism, increase the visual field and beautiful bridge shape. In our country, the overturning accident of single-column pier bridge is mainly due to the serious overload of heavy vehicles in our country, and the safety performance of single-column pier is reduced when the overload is 1.6 times. In pavement design, it is recommended that 100 tons of super heavy standard trailers drive slowly from the middle lane. This will reduce the possibility of bridge overturning.

According to a draft of technical code for on site inspection of highway bridges issued by the Highway Research Institute of the Ministry of transport last year, the number of highway bridges in China is large, and most of them have been in service for more than 15 years.

According to the data, the earliest collapse accident of single pier in China occurred at 11:00 p.m. on October 23, 2007. When three semi-trailer heavy trucks were driving from south to north to the viaduct of Minzu East Road in Baotou City, the bridge deck suddenly overturned, resulting in the interruption of special railway line under the bridge.

Since then, similar accidents have occurred one after another. In July 2009, three seriously overloaded vehicles were parked intensively and deviated from the lane in order to avoid the retrograde vehicles in front of the continuous single-column pier ramp bridge outside the harbour and pond toll station of Jinjin Expressway, resulting in overturning accident of the bridge, 5 trucks falling, resulting in 6 deaths and 4 injuries.

In the early morning of February 21, 2011, the approach pier of Chunhui overpass in Shangyu City, Zhejiang Province collapsed, with a total length of 120 meters and a maximum drop of 7 meters. The accident caused 4 trucks on the approach bridge to roll over and 3 people were slightly injured.

In 2013, the Henan Provincial Department of Transportation issued the Notice on Strengthening the Maintenance and Management of Highway Single Pier Bridge Construction on its official website. The Notice said, As one of the common forms of highway bridge structure, single pier bridge is widely used in highway, ordinary highway and urban viaduct projects in our province. However, in recent years, overturning accidents of single-pier bridges caused by overloading of transport vehicles have occurred from time to time, causing not only heavy losses of personnel and property, but also great negative social impacts.

Notice requires that improve the anti-overturning vehicle load standard of bridges, attach importance to the construction and transformation of single-column pier bridges, carry out special investigation of single-column pier bridges, establish the project library of single-column pier bridge transformation as soon as possible, and study and formulate technical guidance for strengthening and transformation of single-column pier bridges on expressways and ordinary highways. Experts said that at present, many provinces and municipalities in China have carried out a survey of the overturning stability of single-column pier bridges and disposed of bridges that need to be repaired and strengthened. The solution to the hidden danger of overturning single-column pier is to add concrete-filled steel tube columns on both sides of the original single-column pier, so that the original single-column pier becomes three-column pier. Source: First Financial Editor: Yang bin_nf4368

Notice requires that improve the anti-overturning vehicle load standard of bridges, attach importance to the construction and transformation of single-column pier bridges, carry out special investigation of single-column pier bridges, establish the project library of single-column pier bridge transformation as soon as possible, and study and formulate technical guidance for strengthening and transformation of single-column pier bridges on expressways and ordinary highways.

Experts said that at present, many provinces and municipalities in China have carried out a survey of the overturning stability of single-column pier bridges and disposed of bridges that need to be repaired and strengthened. The solution to the hidden danger of overturning single-column pier is to add concrete-filled steel tube columns on both sides of the original single-column pier, so that the original single-column pier becomes three-column pier.