On December 19, aerial photography of the Ezhou section of Hubei Ezhou section of the G50 Shanghai-Chongqing Expressway, the scene of the overturning accident of the approach bridge deck of the expressway. CFP/Picture
What causes the frequent occurrence of bridge rollover accidents? The rollover of the bridge on the Hubei Expressway on December 18 has caused 4 deaths and 8 injuries. The specific cause of the accident is not yet clear. However, in an interview with a reporter from Beijing Business Daily, several experts analyzed that the single-pillar pier bridge had encountered problems. Overloading of the boarding vehicle is the main cause of rollover. On the 19th, Shaanxi Communications Holding Group Co., Ltd. responded to the media saying that the accidental vehicle entered the Lintong Expressway toll station in Shaanxi with complete procedures. Experts pointed out that even after approval, management measures such as traffic control and slow driving of vehicles in the middle are required. There may be management problems in this incident.
At 15:36 on December 18, a bridge rollover occurred on the G50 Huyu Expressway Huahu Interchange D ramp (Huyu Expressway to Daguangnan Expressway ramp). Three trucks passing on the bridge overturned to the same side. On the main and auxiliary roads from Huangshi to Wuhan.
According to Xinhua News Agency, the relevant department obtained the trajectory of the vehicle involved and found that an 11-axle truck with a Shaanxi license plate arrived at the Lintong toll station in Shaanxi at 10:36 on December 14. The total weight of the vehicle was 198 tons. When it rolled over, the large truck broke in two, and other vehicles fell.
According to CCTV reports, at 15:53 that day, the first rescue force of the Ezhou City Fire Rescue Detachment arrived at the scene. Investigations revealed that a 500-meter-long ramp bridge overturned at the scene, three trucks fell and one car was crushed. Technical and tactical measures such as “enclosure and control alert, grouped investigation, cooling and risk relief, fixed car body, demolition rescue, on-site lighting” and other technical and tactical measures were adopted to implement rescue.
At 16:31, the on-site disposal was completed. A total of 7 trapped persons were searched and rescued, of which 4 were injured and 3 died. Some of the injured had escaped by themselves before the fire and rescue forces arrived. So far, the accident has caused 4 deaths and 8 injuries.
It is reported that the Huahu Interchange D-Ramp Bridge is 731.08 meters long. It was completed and opened to traffic on September 28, 2010. The bridge deck is 13 meters wide. The support uses basin-type rubber bearings and the expansion joints use comb-shaped steel plate expansion joints. The upper structure is steel box girder and continuous cast-in-place box girder, and the lower structure is double-column piers and single-column piers, with a design load of 55 tons of highway level 1.
In response to the specific investigation of the accident, reporters from the Beijing Commercial Daily called the Hubei Provincial Department of Transportation and the Traffic Management Bureau of the Hubei Provincial Public Security Department to find out the situation, but the calls were not connected.
This is not the first time that a bridge rollover accident has occurred. As early as August 24, 2012, the approach bridge of Harbin Yangmingtan Bridge overturned, causing 3 deaths and 5 injuries. At around 18:10 on October 10, 2019, the bridge deck overturned at K135 on the 312 National Road in the direction of Shanghai and on the bridge on Xigang Road, Xishan District, Wuxi City, Jiangsu Province, causing 3 deaths and 2 injuries.
Dr. Kong Feng, associate professor of the School of Humanities and Development of China Agricultural University, told reporters from Beijing Business Daily that the common structural feature of these accidents is the single bridge pier. The stability is not enough.
Shan Chenglin, a professor of bridge and tunnel engineering at the School of Civil Engineering and Transportation, South China University of Technology, said in an interview with a reporter from Beijing Business Daily that in order to save space on the bridge, single-pillar piers are used in the middle of the bridge, with two-way supports at both ends, but there is only one support in the middle. This structure will not cause problems if there is no overweight vehicle. If there are overweight vehicles that are driven to one side, it is easy to cause problems.
He added, “In addition, this time the bridge is a steel box girder. If it is a concrete structure, the weight of the concrete itself can be used to balance it, but if it is a steel box girder, the weight is lighter and it is easier to roll over.”
How many domestic applications of this kind of bridge are there? Has it been modified? In this regard, Shan Chenglin said, “Ten years ago, many domestic overpasses, urban viaducts, and expressway ramp bridges all used single-pillar piers. The old standards had relatively low requirements for preventing bridges from overturning. Accidental bridges were Compliant with the specifications at the time. After several bridge rollover accidents occurred in the past ten years, they have attracted attention. The design requirements were increased in about 2018. Bridges designed in accordance with the new requirements have not been accidentally affected. There are still some provinces. It is required to renovate the single-pillar piers on the national and provincial highways, as in Guangdong Province, the renovation has basically been completed.”
Regarding the bridge where the accident occurred, some media learned from the person in charge of Hubei Edong Yangtze River Highway Bridge Co., Ltd. that in November 2020, Edong Bridge Company reinforced the ramp as required, and relevant inspection data showed that the ramp had no quality problems. The company unilaterally believed that the cause of the accident was caused by overloaded trucks.
In response to bridge-related issues, a reporter from Beijing Commercial Daily contacted Edong Bridge Company through the phone reserved by Tianyancha, but no one answered the call.
Overloaded truck “complete procedures”
In Kong Feng’s view, vehicle overload is often the most important cause of viaduct rollover. He explained that, often due to vehicle overload and relatively concentrated load distribution on viaducts, the instability effect caused by eccentric loads greatly exceeds the stability effect of the bridge superstructure, causing the failure of the stability effect of the bridge support. Relative sliding and rotation occurred between the beams and piers of the bridge, which caused the beams to slide and overturn to the ground.
It is understood that the section of the high-speed bridge that was involved in the rollover incident was opened to traffic in 2010, with a weight limit of 49 tons. The vehicle involved in the incident departed from Lintong three days ago, and the substation equipment with a load of 198 tons while driving was 400% overweight.
Can overloaded trucks get on the bridge? Zhang Zhuting, a professor at the School of Management of the Ministry of Communications, said in an interview with a reporter from Beijing Business Daily that bulky transportation is divided into two categories, one is approved and legal, and the other is unauthorized illegal behavior. It depends. Whether the truck involved has completed the relevant procedures. At the same time, it is necessary to check which bridge to use for bulky transportation.
According to a report from China Business Daily on December 19, Shaanxi Communications Holding Group Co., Ltd. stated that the accidental vehicle entered the Lintong Expressway toll station in Shaanxi with complete procedures and was therefore released. The specific traffic conditions are temporarily unknown. At the same time, the Southern Metropolis Daily reported that the Shaanxi Provincial Expressway Toll Center responded that the large truck involved was a high-speed from the Lintong toll station and was a legally passing large-scale transportation vehicle, and the relevant department escorted the truck to The provincial boundary between Shaanxi and Henan.
How to build a fortress of management
The procedures for overloading vehicles are complete, and the bridges have been reinforced and reconstructed. Why does a tragedy occur? Shan Chenglin explained to a reporter from Beijing Business Daily that although the bulky truck is heavy, the wheelbase of the wheels is relatively open, and the bridge can be crossed after verification. In fact, this incident also had some management problems.
“Because it is stipulated that there must be traffic control when large-size transport vehicles go on the bridge, and other vehicles cannot go up at the same time. The other vehicles can only go on the bridge after the large-size vehicle has passed the bridge.” Shan Chenglin said, “In addition, large-size vehicles When the transport vehicle is on the bridge, it must be driven slowly in the middle. This time the large transport vehicle ran to the side, which is also not in compliance with the regulations. If the management is in place, there may be no problems.”
In Kong Feng’s view, not only should we constantly pay attention to overload management, but also lifeline systems such as viaducts should establish a full-process normalized risk identification, risk monitoring, risk assessment, risk consultation, risk communication and risk disposal mechanism in the future.
“On the one hand, we must pay great attention to the potential risk assessment of heavy vehicles passing through viaducts in densely densely populated areas, and accurate assessment of the restrictions on trucks passing through viaducts intensively. The management must be strict. At the same time, the safety of viaducts and bridges must be routinely checked and maintained regularly; on the other hand, do a good job. Publicity of risk science has enabled the urban construction department to pay attention to the weight limit of the viaduct. The supervision and law enforcement of overloaded and over-limit vehicles must be strict and punished before and after, and punish individuals, enterprises, markets, and construction sites that violate the regulations.” Kong Feng said.
Source: Beijing Commercial Daily
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