報告書番号

303

タイトル（和文）

基礎と地盤の動的相互作用を考慮した変電機器の耐震設計に関する研究

タイトル（英文）

EARTHQUAKE RESISTANT DESIGN OF ELECTRIC SUBSTATION EQUIPMENTS CONSIDERING DYNAMIC SOIL-FOUNDATION INTERACTION

概要 （図表や脚注は「報告書全文」に掲載しております）

本論文は変電機器の耐震設計法を確立するために、変電機器の耐震上の弱点を抽出するための地震被害調査、耐震上の特徴を把握するための変電諸地盤、基礎および変電機器の調査・検討、設計地震動を検討するための４変電所における地震観測、モデル地盤による地震動増臨特性の検討および加速度期待値の推定、変電機器と地盤との動的相互作用を検討するために必要な地盤モデル化手法についての検討等を行い、これらの成果に基づいて以下の提案を行った。（１）地表面における設計地震動として「０．３Ｇ共振正弦２～３波」（Ｇ：重力加速度）、（２）基礎・地盤系固有振動数ｆ０と機器固有振動数ｆ１との比ｆ１／ｆ０を用いた設計法により、がいし型機器用設計地震動として「Ｓ波速度１５０ｍ／ｓ以上の地盤に設置されるがいし型機器に対しては０．３Ｇ共振正弦３波」、基礎９ｍ以上の基礎またはｆ１／ｆｏ０．７の変圧器のブッシング用設計地震動として「０．６

概要 （英文）

THIS THESIS PROPOSES A EARTHQUAKE RESISTANT DESIGN METHOD FOR SUBSTATION EQUIPMENT AFTER INVESTIGATING EXAMPLES OF DAMAGE BY EARTHQUAKES IN THE PAST AND THEIR CAUSES,PROSPECTING CONDITION OF SOILS,FOUNDATIONS,AND EQUIPMENT CHARACTERISTICS AT SUBSTATIONS,CARRING OUT THE IN-SITU VIBRATION TESTS AT SUBSTATIONS TO STUDY DYNAMIC INTERACTION PROBLEM BETWEEN SOIL AND FOUNDATION,AND ANALYZING THE COUPLEDMOTION OF THE EQUIPMENT-FOUNDATION-SOIL SYSTEM UNDER EQRTHQUAKE.THE MAIN RESULTS OBTAINED CAN BE SUMMARIZED AS FOLLOWS. (1)INPUT OF TWO OR THREE CYCLES RESONANT SINUSOIDAL WAVE WITH 0.3G ,WHICH IS TWO OR THREE CYCLES OF SINUSOIDAL WAVE THAT HAVE A NATURAL FREQUENCY OF EQUIPMENT WITHAN AMPLITUDE OF 0.3G(G=ACCELERATION OF GRAVITY),IS CONSIDERED APPROPRIATE AS DESIGN EARTHQUAKE MOTION ON SUBSTATION GROUND SURFACES. (2)AN EQUIPMENT EARTHQUAKE AMPLIFICATION FACTOR CAUSED BY THE EXISTENCE OF THE FOUNDATION AND SOIL SYSTEM CAN BE EASILY CALCULATED BY USING THE RATIO F1/F0 BETWEEN THE NATURAL FREQUENCY OF EQUIPMENT F1 AND THE NATURAL FREQUENCY OF FOUNDATION AND SOIL SYSTEM F0.1T IS POINTED OUT THAT SEISMIC DESIGN OF SUBSTATION EQUIPMENT CONSIDERING THE INTERACTION BETWEEN FOUNDATION AND SOIL CAN BE MADE EASILY BY USING THE RATIO F1/F0. (3)IT HAS BEEN MADE KNOWN THAT PORCELAIN-CLAD EQUIPMENTS INSTALLED ON SOIL WHOSE S-WAVE VELOCITY IS GREATER THAN 150M/S MAY BE DESIGNED BY THE METHOD OFTHREE CYCLES RESONANT SINUSOIDAL WAVE INPUT WITH 0.3G AND THAT BUSHINGS FOR ULTRA SUPER HIGH VOLTAGE TRANSFORMERS MAY BE DESIGNED BY THE METHOD OF THREE RESONANT SINUSOIDAL WAVE INPUT WITH 0.6G OR ABOUT IT FOR THE SAME SOIL CONDITIONS.

報告者

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