Li Chun Builds the Zhaozhou Bridge

The Zhaozhou Bridge, also called the Anji Bridge, stands over the Xiao River south of Zhao county, Hebei; it takes its name from Zhao county's old name, Zhaozhou, and is known locally as the “Great Stone Bridge.” It was designed and built under the direction of the outstanding Sui craftsman Li Chun, around the end of the Kaihuang era to the start of the Daye era (about AD 595–605), over 1,400 years ago, and is the oldest and best-preserved open-spandrel single-arch stone bridge in the world. The bridge is about 64 m long, its main arch spans about 37 m, and the deck is about 9 m wide, built of 28 independent arch rings set side by side. It has several innovations. First, a single large segmental arc, a flat arch that eases the passage of carts and people and saves stone. Second, two small arches on each shoulder of the main arch, forming an “open spandrel,” which lightens the bridge and saves stone, increases flood discharge in high water and reduces the force of floods on the structure, while making the bridge lighter and more beautiful. Third, the arch rings are joined and reinforced with iron clamps and tie rods, making the bridge strong and durable. Over the centuries the bridge has withstood many floods and earthquakes and still stands and can be crossed, a full demonstration of the wisdom and skill of ancient Chinese builders. Similar open-spandrel arch bridges appeared in Europe only in the 14th century, over 700 years later. The balustrade panels carry fine reliefs of dragons and beasts. In 1991 the American Society of Civil Engineers named the Zhaozhou Bridge an International Historic Civil Engineering Landmark.