New Horizons in Structural Design April, 2008
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構造デザインの最前線    FACT NIKKEN SEKKEI15Building Performance Supported by Actual Measurements: Midland SquareMidland Square, a 247-meter-high building in Nagoya City, has many notable structural design features. The center of the building features a multi-story steel plate wall tube that works like the central pillar of a pagoda providing both strength and flexibility. Midland Square is the first super high-rise building to use high-tensile-strength steel plate walls (with a surprising strength of 780N/mm²). This type of wall rigidly reinforces the first and the second floors, which are the core bases of a super high-rise building. In planning Midland Square, a damping structure has been adopted. It is necessary to use suitable damping mem-bers and dampers with different effective ranges. In Midland Square, we improved safety and habitability for a wide vari-ety of sway types. In the case of a massive earthquake, the toughness of the framework is important. In addition, the ATMD on the 43rd floor and the outrigger-style oil dampers improve habitability by reducing the extent and duration of sway. Connection of the high-rise building to the low-rise building using oil dampers also helps diminish sway.Recently, more building projects have introduced con-crete-filled steel tubular columns (CFT) to support larger loads. Midland Square is the first example of adoption of fill-ing concrete of 100 N/mm² for high-performance steel tubes of 590 N/mm² for use as columns subject to high axial force.In super high-rise buildings, it is important to accumulate data through full-scale verification experiments. For Midland Square, we were allowed to implement experiments with critical full-scale parts essential in realizing the required quake-resistant functions. By confirming their capacities, we ensured excellent actual performance. Super high-rise build-ings must be examined from many perspectives through design and analysis. Comprehensive formulation of perfor-mance based on consideration of total balance is becoming more important than ever, despite specialization in all design and construction processes.パイルドラフト基礎多段拡径高支持力杭Piled raft foundation多種多様な揺れに対応する3種類の制振システムThree types of vibration-damping systems高張力鋼780N/mm2鋼板壁の性能を検証Verifying high-tensile-strength steel walls高張力鋼780N/mm2の鋼板壁。頑丈な足元を構成する。High-tensile-strength steel walls of 780N/mm2連結オイルダンパー (7F)※Connecting oil dampers (7F)アウトリガー方式オイルダンパー(7、26、42F)※Outrigger-style oil dampers (7, 26, 42F)ATMD(43F)※※AMD(Active Mass Damper)  ATMD(Active Tuned Mass  Damper)建物の頂部で、別の質量(付加質量)を揺らすことで、建物の揺れのエネルギーを吸収するもの。このうち、付加質量の動きをコンピュータで制御する機構のことをAMD(Active Mass Damper)といい、ばねなどにより、建物の揺れの特性にあらかじめ合わせた機構のことをTMD(Tuned Mass Damper)という。AMDとTMDの2つの性能を組み合わせた装置をATMDと呼び、具体的には、ある程度の揺れに対しては、AMDとして働き、大きな揺れになると制御を開放し、TMDとして揺れを制御する。※ダンパー建物に作用する地震力(エネルギー)を吸収する装置のこと。アイソレータとの併用で、地震時の建物の揺れを効果的に小さくする。ダンパーの1種として、シリンダー内に粘性体を充填したオイルダンパーなどがある。

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