The five bridges are being repaired at different phases so that visitors to the Tian'anmen Rostrum and the Forbidden City will not be affected, according to the People's Daily.
The repair is made in accordance with a plan approved by the Beijing Municipal Administration of Cultural Heritage on Nov. 6, 2008.
A public bidding posted on the administration's website said the total budget for the renovation project is 946,400 yuan (about 139,000 U.S. dollars).
The five vaulted bridges were initially constructed in 1420 during the the Ming Dynasty (1368-1644) and were rebuilt in 1690 during the Qing Dynasty (1644-1911).
The bridge in the middle, also the biggest, is 23.15 meters long and 8.55 meters wide. It was only used by emperors for entering and coming out of the Forbidden City in the past.
(Xinhua News Agency February 20, 2009)