Ronald G. KNAPP

The segmented open spandrels (arches) that support the Zhaozhou Bridge, built during the Sui dynasty, were a Chinese innovation. Such engineering allowed the bridge to span a wide river and accommodate boat traffic.
The Zhaozhou Bridge, built between 595 and 605 CE, is the world’s first large segmental arch bridge, making possible a near-level span of a broad river in North China. The innovation of open spandrels—arch-shaped openings—in the triangular