Bridges along the Pinglu Canal: A testament to engineering, community, and ecological harmony

Photo shows the newly completed Qinjiang Bridge over the Pinglu Canal in south China's Guangxi Zhuang autonomous region. (Photo/Xu Zhigan)

The Pinglu Canal, the first major river-to-sea canal project planned and coordinated at the national level since the founding of the People's Republic of China, is scheduled to open to navigation on September 16, 2026. Construction began on Aug. 28, 2022, with a total investment of about 72.7 billion yuan (about $10.83 billion).

Stretching 134.2 kilometers, the canal starts at the mouth of the Pingtang River in the Xijin Reservoir area of Hengzhou, Nanning, south China's Guangxi Zhuang autonomous region. It runs south through Luwu town in Lingshan county, Qinzhou, before connecting with the Qinjiang River and flowing into the Beibu Gulf. Designed to Class I inland waterway standards, it is China's highest-grade navigable canal, capable of accommodating vessels of up to 5,000 tonnes.

Once operational, the canal will shorten the inland waterway route for cargo from southwest China to the sea by more than 560 kilometers compared to traditional routes. It will also significantly reduce shipping distances to major ASEAN ports, lower overall logistics costs by 18 to 30 percent, and save more than 5 billion yuan in transportation costs each year.

The Pinglu Canal features 104 bridges along its route, including 27 crossing the canal itself, as well as numerous supporting structures such as trestle bridges, temporary bridges, and pedestrian bridges that have been rebuilt or newly constructed. This extensive network has earned the project the nickname "Hundred-Bridge Project." These bridges do more than connect the two banks of the canal; they also reflect the region's cultural heritage, improve local livelihoods, and demonstrate a commitment to harmony between people and nature.

In Qinzhou, where the canal meets the sea, the Zicai Bridge officially opened to traffic on April 28.

"The original Zicai Bridge lacked the navigational clearance required for 5,000-tonne vessels on the canal and had to be removed," said Yuan Mingyang, deputy director of the engineering management department at Guangxi Pinglu Canal Construction Co., Ltd., the builder of the canal under Pinglu Canal Group. "However, as a self-anchored suspension bridge with a complex load-bearing structure, improper demolition could have caused it to collapse."

Photo shows the completed Beibu Gulf Bridge over the Pinglu Canal in south China's Guangxi Zhuang autonomous region. (Photo/Xu Zhigan)

To dismantle the bridge safely, the project team invited experts to conduct simulations using digital twin and BIM (Building Information Modeling) technologies. They ultimately adopted a reverse dismantling method. "Taking the bridge apart in the reverse order of its construction. The demolition alone took more than half a year," Yuan said.

Another notable structure, the Qinjiang Bridge on the G75 Lanhai Expressway, is the world's largest-span and heaviest concrete-filled steel tube arch bridge to be lifted as a single unit. At peak times, it previously handled more than 100,000 vehicle trips per day. To minimize disruption, the construction team used the old bridge as a platform for transporting construction materials.

"Half of the bridge was enclosed with scaffolding and protective nets for construction, while the other half remained open to traffic -- a rare approach in conventional bridge construction," said Kuang Zhiqiang, a person in charge of the bridge's construction. The team also employed an overall lifting technique: assembling bridge components on the ground before lifting them into place. Installation was completed in just 16 hours.

"The Pinglu Canal is a complex, integrated project involving multiple disciplines, including waterways, hubs, slopes, bridges, and ecology. The entire project was divided into more than 180 construction sections, with over 20,000 workers involved at peak periods. It posed major challenges in organization and coordination," said Cheng Yaofei, chairman of Guangxi Pinglu Canal Construction Co., Ltd.

As China's first smart canal featuring full life-cycle management, the Pinglu Canal's digital twin platform integrates multidimensional data on weather, hydrology, construction schedules to simulate operations in advance and automatically generate optimal construction plans. For example, one side of the waterway is drained for earth excavation and foundation work. Once that side is completed, work shifts to the other. This carefully staggered approach, both in time and space, has helped minimize interference between construction activities.

Photo shows an ecological corridor bridge over the Pinglu Canal in south China's Guangxi Zhuang Autonomous Region. (Photo/Ji Haixin)

The project stands as a testament to development driven by a deep commitment to people's well-being.

The site of Qinjiang Bridge was once home to the Qinjiang No. 1 Bridge, built in 1958 as Qinzhou's first urban bridge. Local residents had deep emotional ties to it. To preserve the city's collective memory, the proposal to retain the old bridge piers was adopted. Today, the new bridge incorporates the preserved piers and provides space for public activities beneath it. A miniature replica of the old bridge has also been rebuilt upstream.

From Qinzhou Oyster Plaza, visitors can see a graceful white bridge spanning the Pinglu Canal: the Beibu Gulf Bridge, voted by the public as the "most beautiful bridge" along the canal. Traffic flows across the bridge, while mangroves thrive beneath it. As a vital coastal wetland ecosystem, mangroves serve as an important barrier for coastal ecological protection.

During construction, the project team adjusted the location of the temporary traffic bridge for the Beibu Gulf Bridge based on recommendations from forestry authorities, avoiding areas with concentrated mangrove growth. Protective measures, including the installation of barriers, were also taken to prevent industrial wastewater and construction waste from entering the mangrove areas, safeguarding the coastal ecosystem.

From the planning stage, the Pinglu Canal embraced the concept of a "green canal," integrating environmental protection throughout the entire project. Efforts have been made to preserve ecosystems along the canal and protect biodiversity.

No asphalt, no road markings -- just a thick layer of soil covering the bridge deck. This is the most distinctive bridge along the Pinglu Canal: an ecological corridor bridge. It is China's first bridge built exclusively as a wildlife crossing over a canal.

The bridge deck recreates the original forest environment, providing shade, food and shelter for wildlife. It allows native species such as spotted linsangs, leopard cats and Pallas's squirrels to move safely through the area, striking a balance between infrastructure development and ecological conservation.