By Xin Dingding (China Daily)
Updated: 2007-08-14 09:22

More than 6,000 damaged or dangerous bridges will be fixed or rebuilt under an ambitious plan to make China's major roadways safer by 2010.

Figures from the ministry's annual report on road maintenance found that by the end of 2006, some 6,300 of China's 500,000 or so bridges were graded "fifth rank", defined as "in dangerous status with some important structural components seriously damaged".

"China should learn a lesson from the collapse of the Mississippi bridge, and accelerate the inspection of unsafe bridges," Xiao Rucheng, secretary-general of the Institute of Bridge and Structural Engineering affiliated to the China Civil Engineering Society, said.

The Ministry of Communications plans to render safe all bridges on state and provincial highways as well as a majority on county roads in three years.

"Priority will be given to unsafe bridges on state highways and bridges with long spans," it said in a document.

The ministry has given guidelines to local bureaus to inspect the status of bridges. It will also fund the projects, though it declined to reveal the total figure.

From 2000 to 2005, the ministry spent 15 billion yuan ($1.97 billion) to repair 7,000 bridges. It also put in place a maintenance system requiring all highway and toll road operation companies to employ bridge engineers to monitor the structures.

China has built many of its bridges in the past two decades, said Xiao, who is also a professor at Shanghai-based Tongji University.

"In the past, designing a bridge needed at least one year, but now it usually takes one month. You can even find bridge designers working overnight to finish the task."

Construction companies sometimes rush their work, possibly leading to design and building flaws, he added.

"I once saw workers asked to join the two sections of a new bridge during a severe typhoon, simply because the construction schedule was set a long time earlier. Cracks are very likely to emerge if concrete is poured in such weather," he said.

Other problems include natural corrosion, age, structural cracks and outdated design standards.

"Many bridges were designed and built 20 years ago, when designers did not predict the huge traffic flows today," he said.

Such factors have led to a number of bridge collapses, whose number is difficult to calculate because of local government cover-ups, he said.