報告書番号

381039

タイトル（和文）

ＵＨＶ赤城実規模試験線の動的試験－鉄塔基礎の試験結果とその力学的モデル－

タイトル（英文）

VIBRATION TESTS OF PROTOTYPE UHV ELECTRIC TRANSMISSION TOWER OF AKAGI -FORCED VIBRATION TEST OF TOWER FOUNDATION-

概要 （図表や脚注は「報告書全文」に掲載しております）

我国の基幹系統は，従来の２７５ＫＶより逐次５００ＫＶへ切換が進められているが，将来の電源立地・系統容量からＵＨＶ送電電圧が必要となることが予想されている。ＵＨＶ送電線は大電力を長距離間に送電する基幹送電線であるため，高い信頼性と我国の厳しい自然条件に適合した合理的な設計が要求される。このため赤城の実規模試験線を用いて動的安定性を検討し，地震・風等の動的荷重に対する安全性評価を行った。本報告は鉄塔基礎の動的挙動について述べており，上下振動・水平振動における基礎の動特性・主脚材といかり材の応力特性が把握されている。また動特性を良く表現しうる数値モデルの作成法が検討され，半無限弾性理論・くい理論・群ぐい理論から得られるモデルが実験結果を良く表現することが判った。これらの成果は，鉄塔の動的安定性評価に直接適用され，現行設計手法によりＵＨＶ鉄塔を設計しうることが得られた。

概要 （英文）

IN-SITU TEST OF UHV AKAGI ELECTRIC TRANSMISSION TOWER FOUNDATION WERE CARRIED OUT. IT WAS A PURPOSE OF FORCED VIBRATION TEST TO OBTAIN DYNAMIC CHARACTERISTICS OF THE ACTUAL FOUNDATION AND MATHEMATICAL MODEL, THE BEHAVIOURS OF WHICH FIT TO THE TEST RESULTS. RESULTS OBTAINED ARE AS FOLLOWS. 1) CHARACTERISTICS OF FOUNDATION BY VERTICAL EXCITATION 1 RESONANCE CURVES WERE REGARDED AS SINGLE DEGREE OF FREEDOM. ITS PROPER-FREQUENCY WAS 25 HZ. 2 SSI SPRING CONSTANT WAS NOT CHANGED BY SIDE EMBEDMENT BECAUSE THE FOUNDATION HAS 4 PILES. 3 RESONANCE CURVES CALCURATED BY NUMERICAL MODEL AGREED WITH THOSE MEASURED IN GOOD ACCURACY. THE VARIOUS CONSTANTS OF THE MODEL WERE DETERMINED AND EVALUATED ON THE THEORY OF ELASTICITY. 2) CHARACTERISTICS OF FOUNDATION BY HORIZONTAL EXCITATION. 1 RESONANCE CURVES WERE REGARDED AS 2 DEGREE OF FREEDOM THAT IS SWAY AND ROCKING. 1ST PROPER FREQUENCY AND 2ND ONE WERE 12 HZ AND 22 HZ,RESPECTIVELY. 2 RESONANCE CURVES AND MODE SHAPES OF THE MODEL SEEM TO FIT PRACTICALLY TO THOSE MEASURED BY TEST. THE CONSTANTS OF THE MODEL WERE EVALUATED AS MENSIONED ABOVE. COMPLEX STIFFNESS OF PILES WERE ESTIMATED AS ONE OF EQUIVALENT SINGLE PILE ON THE BASIS OFTHEORY PRESENTED BY VESIC AND CHANG. IT WAS FOUND THAT THE EVALUATED STIFFNESS WAS REASONABLE, COMPARING WITH EXACT SOLUTION.

報告者

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