The Izumo Dome, Largest Timber Structure in Japan

An all-weather, multi-purpose facility, the Izumo Dome, was recently constructed in Japan. This structure covers a free space 143 m in diameter and reaches a height of 49 m. A note-worthy aspect of the dome is its hybrid structural system. The timber structure resembles a Japanese traditional umbrella. Coupled beams made of large section glued-laminated (glulam) timber were used for the radial arch members. Steel ring cables and diagonal steel rods were employed to increase the dome's stability. A translucent coated glassfibre fabric was used for the roofing. The structure was raised by a "push-up" erection procedure in a period of just a few days. Weather conditions were carefully considered in designing the dome. Since strong westerly winds prevail year-round in Izumo, a horseshoe-shaped embankment was provided around the northeast side of the structure.