報告書番号

U90027

タイトル（和文）

１９８９年ロマ・プリエータ地震による電力設備の被害と復旧に関する調査

タイトル（英文）

INVESTIGATION OF SEISMIC EFFECT AND RESTORATION OF ELECTRIC POWER FACILITIES DUE TO 1989 LOMA PRIETA EARTHQUAKE

概要 （図表や脚注は「報告書全文」に掲載しております）

最適な電力流通システムの地震被害予測法と復旧対策法を立案するための基礎資料を得ることを目的として，１９８９年米国カルフォルニア州で発生したロマ・プリエータ地震による電力設備被害の実態と復旧の経緯について調査を行った。今回の地震では，発・送電設備には顕著な被害は認められなかったが，変電所機器のうち高重心型の碍子型遮断器が１１台も倒壊し，地震後の電力供給の大きな障害となった。地震直後には震源域からサンフランシスコ湾岸部にかけての広い範囲で約１４０万軒の需要家が停電となったが，系統切換え操作や迅速な遮断器の交換により大半の地域では２４時間以内に停電を解消することができ，わが国の宮城県沖地震の停電解消状況とほぼ同様な結果であった。また，地震後の停電は，輸送施設，ガス供給施設，上水道施設，下水道施設，工業生産施設などの日常機能に大きな影響を及ぼしたことが明らかとなった。

概要 （英文）

THE SEISMIC EFFECTS AND SUBSEQUENT RESTORATION OF ELECTRIC POWER FACILITIES DUE TO THE 1989 LOMA PRIETA EARTHQUAKE WHICH OCCURRED IN CALIFORNIA,U.S.A.,WERE INVESTIGATED BY RECONNAISSANCEOF THE SAN FRANCISCO BAY AREA. THE PURPOSE OF THIS PAPER IS TO COMBINETHESE FINDINGS WITH CURRENT STUDIES ON THE METHODOLOGY FOR RELIABLE POWER ESTIMATION AND RESTORATION FOR POSSIBLE EARTHQUAKE DISASTERS FOR WHICH ANALYSES OF THE PERFORMANCE OF ELECTRIC POWER SUPPLY SYSTEMS DURINGEARTHQUAKES,THE EFFECT OF POWER OUTAGES AND A PRACTICAL STRATEGY FOR RESTORATION MUST BE ESTABLISHED. ALTHOUGH THERE WAS ONLY MINOR DAMAGE TOPOWER STATIONS AND OVERHEAD AND UNDERGROUND TRANSMISSION LINES IN THE AREA,ELEVEN CIRCUIT BREAKERS WITH HIGH CENTERS OF GRAVITY WERE SEVERELYDAMAGED AT SOME SUBSTATIONS. THIS ESSENTIAL SEISMIC EFFECT WAS DIFFERENT FROM OTHER EVENTS AT ELECTRIC POWER FACILITIES CONSIDERED IN THE INVESTIGATION AND WAS A PRIMARY CAUSE FOR THE EXTENSIVE POWER OUTAGES IN THE AREA. AN ESTIMATED 1,400,000 CUSTOMERS WERE AFFECTED BY POWER OUTAGES IMMEDIATELY AFTER THE EARTHQUAKE. SERVICES WERE RESTORED WITHIN 24 HOURS WITH THE AID OF LOAD TRANSFER AND PROMPT REPLACEMENT OF DAMAGED CIRCUIT BREAKERS EXCEPT WHERE COLLAPSED BUILDINGS AND HOUSES WERE CONCENTRATED. THE TIME TOGET BACK TO NORMAL SERVICE WAS SLMILAR TO THAT FOR THE1978 OFF-MIYAGI EARTHQUAKE IN JAPAN. THSES POWER OUTAGES HAD A MAJOR EFFECT ON TRANSPORTATION,CITY GAS,WATER SUPPLY AND SEWERAGE SYSTEMS,AND THE INDUSTRIAL FACILITIES IN THE AREA.

報告者

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