A new round of maintenance work on the Nanjing Yangtze River Bridge will start at 8 pm on Tuesday and last for three to four days, according to the Nanjing bridge section of the Shanghai Railway Bureau.

Mainly because of erosion caused by rain, the surface of the 44-year-old bridge is marked with 117 potholes, some of which between 7 and 8 centimeters deep and about 50 centimeters long.

In places they are big enough to reveal the bridge's underlying structures, local media reported.

Liu Zhiqing, deputy chief of the Nanjing bridge section, said an inspection of the bridge will start on Tuesday night.

"The inspection will look at the bridge's current structural soundness and whether it can support the amount of traffic now going over it," Liu said.

The local government said the bridge is bearing heavier burdens every day. About 80,000 vehicles now cross it daily, about 70,000 more than it was originally designed to convey.

Since the bridge underwent a large amount of maintenance work in 2002, the local government has made repairs to it almost every year. But that has occurred at specific parts of the bridge rather than along its whole length.

"The prerequisite for repairing the bridge is having enough time to do so," Liu said.