New Horizons in Structural Design April, 2008

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構造デザインの最前線　　　　FACT　NIKKEN SEKKEI33dation on which the table is installed is critical. With a test building in place, the table can weigh up to 2,000 tons. In order to pre-cisely shake the building to an accuracy of 1/20 second, a highly rigid foundation is required. In addition, there is a possibility that such a massive, artificially produced force could cause vibrations throughout the entire neighboring area, with tremors being trans-mitted via the ground. Therefore, careful study was essential. For E-Defense, we planned a massive foundation of approximately 200,000 tons, using 90,000 cubic meters of concrete. We con-trolled the risk of neighborhood vibration by positioning the foun-dation in a valley-shaped location in order to enable the founda-tion and the bedrock to work together. Furthermore, we constructed a concrete plant on the site in the design stage to produce high-quality concrete, and we studied the construction procedure in collaboration with the builder. The result was a strong foundation with no cracks. E-Defense contributes to the progress of aseismic technology by providing a shaking table and a founda-tion that deliver high performance. Structural Design for Continued Scientific Progress Nikken Sekkei's specialized expertise has resulted in advanced sci-entific facilities such as Super-Kamiokande, which came under the spotlight for its Nobel Prize-winning research contributions, as well as the E-Defense facility introduced here. We have also proposed technological solutions involving a range of stringent design condi-tions, including vibration specifications for semiconductor manu-facturing plants. E-Defense is a product of today's most sophisti-cated technologies supported by our cumulative experience. It is an excellent example of one way in which structural design can contribute to scientific progress.Mikio Yoshizawa, Yuji Yamano, Satoru Fukai油圧源棟配管ピット次造成ライン　＋Aerial view of E-DefenseE-ディフェンス空撮E-Defense is built on a highly rigid foundation.E-ディフェンス計測制御棟・実験棟・油圧源棟の断面。正確な震動をつくり、かつ施設外に振動を伝えないため巨大な基礎が構築されている。A shaking test was conducted on a six-story reinforced concrete building to verify actual performance.実大6層鉄筋コンクリート造建物の震動台実験（2006年1月・文部科学省『大都市大震災軽減化特別プロジェクト』）資料提供：独立行政法人防災科学技術研究所 兵庫耐震工学研究センター

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