Beijing Sanyuan Bridge overhaul

By one-in-one 1000-ton loading frame, laser tracking and satellite navigation, overall replacement of bridge was completed within 43 hours.

In large cities with heavy traffic, the contradiction between bridge maintenance and traffic congestion is a worldwide problem. Beijing Sanyuan Bridge is located at the intersection of highways and urban expressways, with an average daily traffic flow of 206,000 vehicles, 48 bus routes and 727,000 daily passengers. The bridge is 55 meters long and 48 meters wide.

If the deteriorated main beam was replaced by traditional technology, the main road would be cut off for 90 days, causing great social and economic losses as a result.

The project developed the first international one-piece machine for the rapid integral replacement of 1000-ton-class bridge. The key technologies of old bridge demolition, new beam transportation, high-precision installation in place, construction monitoring and other key technologies were systematically studied, and a precise positioning control system based on laser tracking and satellite navigation was developed.

In forty-three hours, the integral replacement of the three-span continuous beam was carried out by using two-pack-frame machine. The time of occupancy due to the construction was reduced by 97.8%, compared with the traditional technology.

During the construction the overpass ramp was used to ensure the smooth flow of public transportation by means of island ring, which reduced the impact on traffic.