Chongqing- The anticipated Hongyan Village Jialing River Bridge was officially opened to traffic in Chongqing, the bridge capital of China, recently surrounded by the sprawling Jialing and Yangtze rivers.

It serves as the first steel double-story high-low tower cable-stayed bridge in Chongqing and another functional mega artwork installation towering above the Jialing River.

Unique parallel fast and slow traffic systems

Hongyan Village Jialing River Bridge is located between Jiahua Bridge and Shimen Bridge, spanning the Jialing River, a tributary of the Yangtze River.

This cable-stayed bridge has multiple towers (or pylons) from which cables support the bridge deck. Its distinctive features are the cables or stays, which run directly from the tower to the deck, forming a series of parallel lines.

The main bridge of the Hongyan Village Jialing River Bridge is 720 meters long, the upper deck is 31 meters wide, with six lanes in both directions, and the lower deck is 27 meters wide, with four lanes in both directions.

In the middle of the lower level is a two-way track designed for Chongqing Rail Transit (CRT), and a bike ramp is built on each side of the track, designed as a slow traffic system. The six lanes on the upper floor are for fast traffic, running cars with a design speed of 80 kilometers per hour.

Bridge aesthetics to depict the locals' characters

With their vast size, unique spatial form, and prolonged existence time, cross-river bridges like the Hongyan Village Jialing River Bridge create or change the urban space and significantly impact urban development, landscape, and citizens' travel experience.

Not only do they achieve efficient traffic demand, but meet people's aesthetic enjoyment.

"The Hongyan Village Jialing River Bridge is a simple, straightforward, and powerful formative art composed of a vertical tower, extended the main beam, and inclined cables," said Lai Yaping, chief designer of the Hongyan Village Jialing River Bridge and deputy chief engineer of Bridge Department of T.Y.LIN International Engineering Consulting (China) Co., Ltd.

He continued that the main beam of the bridge is made of steel stringers and triangular steel stringers, bringing a transparent view. The bridge tower adopts a door-shaped reinforced concrete structure, with the height of the higher tower 202 meters and the lower tower 150.7 meters.

"When we design the bridge tower, we use simple vertical lines to shape the solemn and straight posture of the bridge tower," said Lai. "Through the abstract vertical straight lines combination, we would like to depict people living in the mountain city of Chongqing, with their straight, firm, upward character traits."

Two millimeters adjustment for a 631-ton-segment 

As the first steel double-story high-low tower cable-stayed bridge in Chongqing, the construction of the  Hongyan Village Jialing River Bridge is rigid. The section of the tower and beam is complex, which is a ladder, polygon, and variable shape, driving high-quality construction control.

The weight of a single steel anchor box of the upper tower is 26 tons, with a lifting height is 160 meters. Issues of weather, wind speed, and tower crane attachment are challenging to control the lifting and installation accuracy.

In particular, the main beam of the bridge is a truss structure with 49 segments. The heaviest segment is 631 tons, while the adjustable range of high-strength bolt connection between segments is only two millimeters.

"To this end, we used finite element analysis software to analyze bridge closure and preset real-time monitors during the construction process, and finally achieved zero error millimeter precision closure," said Liu Kang, chief engineer of the Yangtze River Branch of China State Construction Bridge Corp., Ltd., also the construction party of the bridge.

The construction party has built a collaboration platform to integrate the data from all project management systems. The platform takes the Building Information Model (BIM), the foundation of digital transformation in the architecture, engineering, and construction industry, as the carrier, combining project technology, quality, schedule, safety, and other factors.

With the Hongyan Village Jialing River Bridge opened to traffic, Chongqing has formed a channel running through the north and south of the central city, further improving the road network and bringing a more efficient modern comprehensive three-dimensional traffic system.