What is the reason for Wuxi elevated side rollover? On the evening of October 10, a bridge deck rollover occurred at K135 and the Xigang Road across the 312 National Road in Wuxi, Jiangsu Province. Three people were killed and two others were injured. After preliminary analysis, the upper span bridge side overturned transport vehicles were overloaded. Where should I interpret this reason?
Initially identified that the accident was caused by overload
Peng Weibing, a professor at Zhejiang University of Technology, and Dai Fei, an associate professor at West Virginia University, conducted a finite element analysis based on online public information and photos and video data of collapsed scenes.
The team believes that the bridge accident can initially determine that the cause of the accident is the overcapacity of the beam bridge caused by severe overload and eccentric load.
The Wuxi City Accident Rescue Command also affirmed the claim that the over-bridge overturned transport vehicles were overloaded.
Some on-site experts also said that the accident was not caused by the overload of a single vehicle. Several overloaded large trucks passed by, causing the single-pillar pier to move like a seesaw and eventually roll over.
Zhang Qiwei, professor of the Department of Bridge Engineering at Tongji University, told the Journal of Chinese Academy of Sciences that according to China’s current road and bridge design standards, the load level of the first-class highway is Highway-I, which is equivalent to a 55-ton multi-axle vehicle plus several vehicles in a fleet. 20 tons of vehicles, and the distance between vehicles is greater than 10 meters.
According to the on-site news, the accident cargo vehicle has at least five 28-ton cylindrical steel coils, plus the vehicle’s own weight, the total weight of the cargo is more than 150 tons, that is, more than twice the maximum allowed by the industry standard.
“A heavily overloaded vehicle greatly exceeds the design calculation load, especially when the overweight vehicle is walking on the side of the lane, it will generate a large overturning moment. If it exceeds the anti-overturning capability of the single-column bridge, it may cause the bridge to tip over.” Zhang Qiwei said.
Overloading, endless trouble
According to incomplete statistics, at least 17 bridge collapses in China during the 12 years from 2000 were alleged to be related to overloading of trucks.
Since 2010, there have been accidents such as the 2011 Shangyu Chunhui Bridge accident in Zhejiang, the Harbin Third Ring Road Qunli Viaduct in Heilongjiang in 2012, and the 2015 Heyuan-Yin-Guangzhou Expressway Shudao Bridge in Guangdong, which caused many bridges to collapse due to serious overloading of vehicles.
Among them, in the accident of the Third Ring Road Qunjiao Viaduct on August 24, 2012, four overloaded trucks were driving on the outside of the bridge on the Honghu Road at the same time, causing the bridge to continuously slide the steel-mixed beams and the four trucks turned sideways. Three people were killed and five were injured.
After the accident of the Fujian-Guangdong Bridge in 2015, the Ministry of Transport and Transportation issued documents to the provincial and municipal governments and issued a number of measures to further strengthen the illegal over-limit treatment of roads and strengthen the management and maintenance management of highway bridges.
However, the occurrence of the Wuxi accident indicates that the hidden dangers of bridge collapse caused by severe overload have not been cured in China.
“The overload is not cured, and the aftermath is endless!” A traffic problem expert who did not want to be named shouted, “The relevant departments should be called upon to study as soon as possible to incorporate illegal overload and transportation into the criminal law and initiate the legislative process.”
It is difficult to cure by relying on road administration
Zhang Qiwei introduced that the “Regulations on the Management of Over-traveled Vehicles Driving Roads” implemented by the Ministry of Communications in 2016 provided clear provisions on the types, loads and driving requirements of over-limit vehicles, as well as violations and penalties. The agency submits a large-size transportation application and drives in the permitted lanes at the prescribed distance and speed.
Peng Weibing and others believe that from the perspective of urban management, the real-time monitoring and management of overloaded vehicles should be further strengthened in the future.
In addition to strengthening management of overloaded vehicles, in the design of bridges, perfect design calculations make the bridge more solid, and it is also a way to reduce bridge safety accidents. Peng Weibing and other suggestions, it is necessary to further improve the anti-overturn calculation method of curved beam bridges; in addition, in the case of unpredictable load, the final failure mode of the structure (bridge) should be controlled in the design to avoid overturning damage (brittle failure) occurring in strength. Before the ductile destruction.
“Although there are large-scale transportation regulations in the country, violations of regulations are still repeated, and there are still underground conversion factories. It is difficult to cure the problems by road administration, and it is necessary to coordinate with various departments such as road administration, transportation, and vehicle management to solve the problem.” Zhang Qiwei said bluntly.
Resolving the safety accidents caused by illegal overload involves the broad consensus and cooperation of the whole society. It is not only necessary for bridge design and construction units to improve the safety indicators of bridges, supervision and management departments to increase governance, improve management efficiency, and also need transportation owners to enhance safety awareness and avoid Fortunately, no longer illegally overloaded transportation.
It is hoped that such accidents will be eliminated in China at an early date, giving road users a safe driving environment.