報告書番号

385051

タイトル（和文）

ＵＨＶ赤城実規模試験線の動的試験－その（５）鉄塔－架渉線連成系の動的挙動と耐震性－

タイトル（英文）

VIBRATION TESTS OF PROTOTYPE UHV ELECTRIC TRANSMISSION TOWER OF AKAGI-(5)DYNAMIC BEHAVIOR AND ASEISMICITY OF TOWER-CONDUCTOR SYSTEM

概要 （図表や脚注は「報告書全文」に掲載しております）

ＵＨＶ赤城実規模試験線（交流１０００ＫＶ級，３基２径間）の起振実験，地震観測及び数値シミュレーションを行って，その耐震性を検討し現行設計法の妥当性を検証した。主な成果は次の通りである。１．同上試験線の起振実験により，鉄塔の線路方向振動性状には電線拘束の影響が強く表れることを明らかにした。２．同上試験線の地震観測により，最大加速度の増幅率として５倍（線路直角方向）～１０倍（線路方向）程度の値を得た。３．鉄塔を等価な梁モデル，電線をピン結合直線棒要素で表した数値モデルを用いれば，起振実験，地震観測の結果を良く模擬し得ることを示した。４．連成系では一様形状の鉄塔群に同位相の地震入力を作用させると安全側設計となること，同上試験線の設計風荷重は約４００ｇａｌの地震に相当すること，現行設計手法で設計したＵＨＶ鉄塔は地震に対して十分安全であること等を明らかにした。

概要 （英文）

FORCED-VIBRATION TESTS,SEISMIC RESPONSE MEASUREMENT AND NUMERICAL SIMULATION WERE CARRIED OUT ON THE PROTOTYPE UHV POWER TRANSMISSION LINE OF AKAGI. ASESISMICITY OF TOWER-CONDUCTOR SYSTEM WAS INVESTIGATED AND THE CURRENT DESIGN STANDARD WAS FOUND TO BE VALID. THE MAIN RESULTS ARE AS FOLLOWS. 1.FORCED VIBRATION TEST RESULTS INDICATED THAT DYNAMIC BEHAVIOR OF TOWERS IN THE LONGITUDINAL DIRECTION ISSTRONGLY INFLUENCED BY THE CONSTRAINING EFFECT OF CONDUCTORS. 2.SEVERAL EARTHQUAKE RESPONSE RECORDS WERE OBTAINED AND THE MAXIMUM ACCELERATION AMPLIFICATION FACTOR OF THE TOWER RELATIVE TO THE GROUND RANGES APPROXIMATELY FROM 5 (IN THE TRANSVERSE DIRECTION) TO 10(IN THE LONGITUDINALDIRECTION). 3.NUMERICAL SIMULATION OF THE FORCED-VIBRATION TESTS AND EARTHQUAKE RESPONSE OF THE TEST LINE GAVE A FAIRLY GOOD EATIMATE OF THE TESTS RESULTS AND EARTHQUAKE RESPONSE MEASUREMENT. IN THE SIMULATION,TOWERS ARE MODELS AS EQUIVALENT BEAMS AND CONDUCTORS ARE EXPESSED AS MANYSTRAIGHT PIN-CONNECTED BARS. 4.NUMERIAL STUDY DEMONSTRATED THAT THE EARTHQUAKE RESPONSE OF TOWER-CONDUCTOR SYSTEM IS LARGER WHEN THE IN-PHASEEARTHQUAKE INPUT IS APPLIED TO EACH TOWER THAN WHEN THE OUT-OF-PHASE INPUT IS APPLIED. IT WAS ALSO DEMONSTRATED THAT THE RESPONSE OF ACTUAL TOWER-CONDUCTOR SYSTEM IS SMALLER THAN THAT OF THE ARTIFICIAL SYSTEM WHOSE TOWERS AND SPANS,ETC. ARE THE SAME THROUGH THE WHOLE SYSTEM. NUMERICAL STUDY ALSO SHOWS THAT THE DESIGN WIND LOAD FOR THE AKAGI TEST LINE IS APPROXIMATELY EQUAL TO 400GAL GROUND ACCELERATION AND THAT TEST LINE CAN WITHSTAND A 600 GAL GROUND ACCELERATION WHEN A FEW MEMBERS IN THE UPPER PART OF THE TOWER ARE REINFORCED. ALL THESE RESULTS INDICATE THAT TRANSMISSION TOWERS DESIGNED BY THE CURRENT DESIGN STANDARD ARE SAFE AGAINST SEISMIC LOADS.

報告者

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