報告書番号

382051

タイトル（和文）

ＵＨＶ赤城実規模試験線の動的試験－その（３）鉄塔単体の試験結果－

タイトル（英文）

VIBRATION TESTS OF A PROTOTYPE UHV TRANSMISSION TOWER (3) -FORCED VIBRATION TEST RESULTS-

概要 （図表や脚注は「報告書全文」に掲載しております）

本報告はＵＨＶ送電線路の耐震性を検証する目的で行われた一連の動的試験のうち，架線前の鉄塔単体の試験結果を述べたものである。主な試験結果は以下のとおり：１．固有振動数と減衰定数１次，２次モードの固有振動数と塔高の関係は既存鉄塔のものと大差なく，ＵＨＶ鉄塔の剛性と重量の比率は在来鉄塔のものと類似している。線路方向と線路直角方向の振動モード形状は，１，２次では類似している。鉄塔の変位－復元力特性が線形の範囲では，減衰定数は１次で０．３４％と小さく，また振幅に対する依存性も認められない。２．鉄塔部材応力度１次振動モードでは底部の主脚材応力度が大きく，２次，３次モードは上部の主脚材，腹材の応力度が相対的に大きくなる。したがって，２次，３次のモードが励起される可能性のある地震に対しては，地震応答解析による検討を要する。

概要 （英文）

FULL-SCALE FORCED VIBRATION TESTS WERE PERFORMED ON NO.2 TOWER(HEIGHT 97M, WEIGHT 294 TON,MADE OF STEEL PIPES)OF THE AKAGI TEST LINE IN ORDER TO CHARACTERIZE DYNAMIC PROPERTIES OF THE TOWER BEFORE CONDUCTOR-STRINGING AND TO ESTABLISH ITS NUMERICAL MODEL. MAIN TEST RESULTS ARE AS FOLLOWS. (1) EIGEN-FREQUENCIES OF THE TOWER IN THE TRANSVERSE DIRECTION WERE SMALLER THAN THE LONGITUDINAL ONES OWING TO THE ROTATORY INERTIA OF CROSS-ARMS.FIRST AND SECOND MODE SHAPES WERE SIMILAR IN BOTH DIRECTIONS. LONGITUDINAL THIRD MODE WAS ACCOMPANIED BY THE TORSIONAL MODE WHEREAS TRANSVERSE VIBRATION HAD PSEUDO-3RD MODE AS WELL AS NORMAL 3RD MODE. LONG AND HEAVY CROSS-ARMS OF THE UHV TOWER SEEMED TO CAUSE THESE COMPLICATED HIGHER MODES. (2) WITHIN THE RANGE OF THE TEST WHERE DISPLACEMENT-RESTORING-FORCE RELATIONSHIP OF THE TOWER REMAINED LINEAR,ITS DAMPING COEFFICIENT WAS RATHER SMALL(0.34% FOR THE 1STMODE),AND ON DEFINITE DEPENDENCY ON THE AMPLITUDE OF VIBRATION WAS OBSERVED. (3) IN THE SECOND AND THIRD MODE RELATIVELY HIGH STRESSES WERE PRODUCED IN MAIN POSTS AND DIAGONAL MEMBERS IN THE UPPER PART OF THE TOWER. (4)FOUNDATION-TOWER INTERACTION WAS NOT PERCEPTIBLE IN THE FREQUENCY RANGE OF 0.5 10.0HZ. IN SOME UPPER PANELS OF THE TOWER, OUT OF PLANE VIBRATION OF DIAGONAL MEMBERS SOMETIMES OCCURRED WHOSE AMPLITUDE SEEMED, HOWEVER,TO REMAIN WITHIN A CERTAIN LEVEL.

報告者

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