In 2012, the reached-standard approach of the in Harbin, China, collapsed because of dangerously overloaded trucks. This accident brought some design consideration issues. As construction companies, the design specifications and investment are no meaning waste budget for considering very uncommon and illegal incident. However, in term of the ethical consideration, the strength and enhancement of the bridge are necessary. Since the issue is overloaded trucks is very common in China, over-design is needed to avoid the same scenario.
Against Changing Standard
With the rapid urbanisation in China, a large number of bridges had been built in last decades for commuting convenience. By occupying the seven of ten longest bridges worldwide, the construction companies, engineering supervision companies, investors and the government got a vast amount of bridge-constructing knowledge and experience. When people need a new commuting bridge, some relevant stakeholders and interests, shows in Table 1, are involved.
The relative standard, JTG-B01-2003 Technical Standard of Highway Engineering, legislated by the Ministry of Communications of the People’s Republic of China. It is well-researched standard and used as a guide for relevant building activities. This clear-cut book is the significant reference for balancing Public finance, public health, public welfare, reputation, law obligation and respect. For this reason, changing it is not a valid measure.
Firstly, one should be taken aware that traffic overloading is the direct cause of the accident of the Yangmingtan Bridge (about 480-500 tonnes, three times as claimed). Also, the companies involved in the construction and the project supervision are qualified and sophisticated, proved by many other projects. According to the accident investigation report and photos from the accident scene, it was a quality-proved structure, evidenced by the bridge body maintaining complete with nearly no cracks after it fell around 7 metres, and the concrete components and the steel structures have experienced little damage and distortion.
Some people have doubted that the single column piers were a flawed design. It has not considered an extreme case like what has occurred. Therefore, the organisation should take the responsibilities. However, it is unfair to do so, since the truck drivers in this accident have seriously against laws and regulations (i.e. Heavy vehicle should drive in the middle lane on a bridge), which claim their obligation of driving safety and respecting the public health. Moreover, the traffic administrates department should also be blamed due to the negligence of duties.
Finally, changing standard is a time-costing and expensive process. Furthermore, the unreasonable high safety factor may indirectly impose a financial waste and budget crisis. Instead of changing the rule, the government has begun to take measures, i.e. to adjust the over-loading punishment, to improve the ability to administrate the engineering projects and traffic controls to avoid an accident. On the other hand, if only improve the structure quality, the truck drivers still take the chance due to lack of punishment hence tragedies like Yangmingtan Bridge may occur again.
In a word, the unreasonable requirement for safety is unacceptable because the desire of safety can be infinite and the investment/budget is limited.
For Improving Standard
Based on the investigation result, it stated that the collapse of the bridge is caused by four overloaded trucks on broad on the same slot of the bridge momentarily. The report mentioned that the structure of design and materials selection of the bridge fulfilled the government and law requirement. However, the doubt about the safety of the government construction from the public has been raised due to this issue. Furthermore, will the accident like Yangmingtan Bridge be avoided in the future if the design of the construction has considered the damage due to the overloading?
According to the statistics, overloaded trucks are frequently found in China (Some report stated that around 80% trucks are overloading). Firstly, this is the consequences of high transportation tax, road user fee and petrol price in China. Secondly, the maximum penalties of truck overloading are 2000RMB (about £200) and disqualify from driving only. As the result, Companies are more willing to pay the fine rather than paying the amount of extra cost to avoid overloading. And also, some vehicle industry use high strength material and unique internal structure to increase the actual load of a truck without indicating on the capacity label to reduce the chances of failing the load check.
Overload is an illegal action, so the truck drivers and the companies have to take the responsibilities. However, the punishment of this should not be losing their life in the ethical perspective. Also, from the police report, about 40% of the truck drivers do not realize that their trucks are overloading, and lots of drivers cannot reject the order from their employers (or lose the job). Hence, by considering the safety of other innocent road users, the collapse of the bridge may affect them or even risk their life. It is unfair that they are suffering from something that they are not responsible.
Regarding the economy, the cost of rebuilding the collapsed bridge is likely to beyond the value of strength enhancing. There is also a huge economic loss due to the delay of transportation. From the public-good aspects, The collapse will result in disrupting the response of the government’s emergency units to the urgent situation, as there are average 9800 vehicles pass Yangmingtan bridge every hour (including a fire engine and police car).
What even the possibility of the bridge collapse causes by overloading is rare, from the above discussion; there is no reason to put human life in danger to save the strength enhancing cost.
Therefore, the design of the bridge should not be just met the government requirement but also taken account of the overload factor to protect the road user and avoid the same disaster happen again.
Economic benefits and ethical considerations are often confronting. The balance and compromise are always checking in engineering fields.