Danjiang Bridge: Engineering Resilience in Northern Taiwan

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In May, a modern piece of infrastructure is opening in a historic part of northern Taiwan.

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And while designed to blend into the environment, like many structures built over the centuries in coastal Tamsui and Bali, the Danjiang Bridge will also have to contend with it.

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During construction there was a time when the wind reached a strength that the entire bridge would vibrate quite rapidly, even the bridge supports were shaking. At that point, workers did not dare to continue working on it.

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Wind, waves, high humidity and heat — along with constant exposure to both salt and fresh water — were just some of the challenges engineers faced while building the nearly one-kilometer-long Danjiang Bridge, linking New Taipei’s Bali District with Tamsui, a popular tourism spot along the Tamsui River.

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First, the bridge tower has a very large foundation and it has to withstand enormous forces. Because this is a river-crossing bridge, the foundation must be a deep foundation. Generally speaking, we use casing drilling machines, and we drive in large circular piles. Based on our understanding in this section of the river, the bedrock slopes on an angle from Tamsui toward Bali. So the closer the bridge is to the Tamsui side, the shallower the foundation depth needs to be.

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The asymmetric span — designed by the late, renowned Iraqi-British architect Zaha Hadid — places its single cantilever on the eastern side, helping preserve views of the sunset while also avoiding disruption to protected wetlands on the Bali side.

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If you’ve been to a temple in Taiwan, the shape of Danjiang Bridge’s pylon should be familiar. (puts hands together as if praying) It’s about 70 floors tall — roughly 40 percent the height of Taipei 101 — and visible for kilometers. But it’s what you can’t see that’s notable. Here, between the ‘praying hands’ — inside is a mass damper, an engineering answer to a familiar problem in Taiwan: earthquakes.

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Seven dampers, each weighing about 750 tons, control shaking during earthquakes. In smaller quakes they transfer the force safely through the bridge, but in stronger earthquakes they activate to absorb energy.

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if the horizontal force becomes too strong we don’t want it to keep increasing without limit. So [the damping mechanism] must have this function to dissipate the horizontal force. We had to design the bridge’s foundation in this way so the horizontal force won’t have adverse effects.

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The end result? A bridge built to take what Mother Nature throws at it. One that has already weathered two massive earthquakes, first in 2024 and again in January this year.

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Taiwan is a region prone to earthquakes and we have experienced relatively large earthquakes during the construction process. However, the epicenter and suppression were not actually located in the vicinity of Tamsui. Perhaps, in fact, earthquakes of magnitude 3 to 4 did not have any impact on the construction of the bridge. We designed [the bridge] to withstand earthquakes of magnitude 7. During the construction process there were earthquakes of magnitude 3 to 4. We did some inspections and basically the earthquakes didn’t damage the construction site and the impact was minimal.

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Over a decade of construction, Danjiang Bridge saw multiple delays caused by COVID-19, material costs and supply chain issues, but it never saw a delay due to earthquakes. Now, with the finish line in sight, its builders are looking to the future.

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I’ve been personally involved from the beginning to now. So for me, this is a very valuable experience. After this bridge is completed I will retire so this is a wonderful ending for my career.

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For the engineers who built it and the residents who will cross it every day, the Danjiang Bridge marks the end of a long journey — and the start of many much shorter ones.

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Designed for long-term use in a challenging coastal environment, the Danjiang Bridge becomes part of Tamsui’s broader landscape of long-standing structures.

Andy Hsueh and Bryn Thomas for TaiwanPlus.