China: New bridge at Kang County combines transportation and architectural aspects

The renovation of an old bridge situated in the heart of Kang County, at Gansu Province, was completed in 2023 by the 3andwich Design / He Wei Studio architect companies. The new bridge aims to reduce traffic congestion by prioritizing pedestrian safety and improving the functionality of the commercial street. In other words, the redesigned bridge provides more diverse and comfortable public spaces while it establishes a new landmark for the town.

Beside the old bridge, there was a commercial street to the north, a kindergarten to the west, and a residential area to the east. However, the mixed flow of pedestrians and vehicles caused safety risks and congestion issues, and impacted both pedestrians and the operational efficiency of the commercial street.

The design was influenced by a nearby corridor bridge that traces its origins to the Qing Dynasty, known as the Dragon and Phoenix Bridge. These corridor bridges, traditional Chinese structures, combine a mix of transportation and architectural aspects. The project prioritized sustainability by retaining the main structure of the original bridge and incorporating timber construction techniques.

The main timbering of the project uses Douglas fir glued wood to reduce environmental impact. In fact, this approach minimizes construction-related emissions and aids in preserving the environment. It is estimated that it results in a total carbon isolation of around 144 tons. Moreover, the project demonstrates sustainability by repurposing the original bridge's white marble breast boards, further minimizing waste, and preserving valuable materials.

The layout of the corridor bridge is the same as the original bridge's design, with a width of 9m and roof height of 7.2m, ensuring clearance for emergency vehicles. The central passage serves a dual purpose as a venue for temporary markets, outdoor performances, and other events.

The corridor bridge is divided into three sections, which are meeting each other at a spacious central point where the portal frame transitions into a single-sided support structure. A tree-shaped steel column and inward curved triangular steel beam add architectural interest to the design.