The world’s longest single-pillar cable-stayed bridge

Interesting Engineering On May 27, it was reported that Taiwan inaugurated the 914 m long Danjiang cable-stayed bridge, connecting the suburbs of Taipei with Bali district, expected to significantly reduce traffic congestion around the Tamsui estuary.

The build uses a unique single-column layout to optimize performance. The main span of the bridge is 450 m long with the tower rising about 200 m above the river surface. Engineers chose a single-column design to reduce the amount of construction work needed underwater. The shape of the bridge was carefully planned to reduce the visual impact on the surrounding landscape due to its proximity to popular riverside viewing areas, while also meeting the requirements for a major traffic corridor.

The bridge deck is about 71 m wide, designed to support many forms of traffic. Separate paths for pedestrians and bicycles are located next to motor vehicle lanes. The project also integrates a light rail line, which is expected to begin operations at a later stage. The Danjiang Bridge will improve transportation links between Taipei and Bali district in northern Taiwan.

Theo New Atlasauthorities estimate the new bridge could reduce travel time by 25 minutes for commuters crossing the river. The route will also reduce congestion on older roads, providing faster journeys for both personal and commercial traffic.

Taiwan lies along active tectonic plate boundaries, making earthquake resistance a key requirement for any major infrastructure project. Engineers designed the Dan Giang Bridge to withstand earthquakes of magnitude 7 or higher by developing a complex seismic support system that can handle both vertical and horizontal forces during an earthquake. The bridge uses a variety of technologies to absorb and redirect seismic energy. Vertical earthquake forces are transferred through bridge piers and cables to the foundation. Lateral forces are managed through hydraulic dampers, friction pendulum bearings and neoprene cushions that help disperse energy, reducing structural stress during seismic activity.

According to the Taiwan Highway Administration, a series of modern sensors are installed on the bridge to monitor the strength, wind force and pressure on the cables in real time. If the indicators exceed safe values, the sensor will warn the bridge control center about the risk of a safety incident so that traffic control measures can be taken to reduce the load.

Theo Engineering and Technologythe Dan Giang Bridge was first proposed nearly 30 years ago but went through decades of environmental assessments, redesigns and multiple failed bids that began construction in 2019. Authorities said the project was once considered too difficult to complete due to its challenging environment and technical requirements.

The project was initially expected to be completed in 2024, but harsh weather, labor shortages and construction difficulties delayed progress by two years. The project has an estimated construction cost of about 400 million USD. Today, the bridge is open to traffic, marking the completion of one of Taiwan’s most ambitious public infrastructure projects in recent times.