報告書番号

U86035

タイトル（和文）

地下空洞の耐震解析手法の実証－発破波動を利用した地下空洞の振動挙動－

タイトル（英文）

VERIFICATION OF EARTHQUAKE RESISTANCE ANALYSIS FOR UNDERGROUND CAVERN -VIBRATION BEHAVIOR OF UNDERGROUND CAVERN BY BLASTING PROPAGATION

概要 （図表や脚注は「報告書全文」に掲載しております）

原子力発電所などの重要構造物を岩盤内地下空洞に収納することを考え，地下空洞の耐震安定性の実証研究の一環として，ここでは，■地下空洞の振動挙動の把握■地下空洞の地震時安定解析手法の実証を目的として，敷地造成工事発破に伴うトンネル振動挙動を，近接する道路トンネル及び周辺岩盤で計測し，数値シミュレーションを行った。トンネル内壁と周辺岩盤の振動波形および振幅に特に顕著な差が認められないこと，ならびにトンネル各点の位相相関が良いことなどから，トンネル空洞の挙動は，岩盤中の波動に追随した変形を示すことが把握された。発破振動計測結果を各種解析法で数値シミュレーションを行った。比較的簡易な計算法である伝達率を用いた静的解析法は動的な有限要素法ならびに境界要素法と同程度の解析精度を示しており，今後の地下空洞の応答解析には，動的有限要素法と同様に伝達率を用いた静的解析法が有効であることを示唆された。

概要 （英文）

BLASTING RIBRATION MEASUREMENTS AND ANALYSISON BEHAVION OF UNDERGROUND TUNNEL HAVE BEEN CARRIED OUT,FOR THE PURPOSE OF SIMULATING THE BEHAVIOR OF A UNDERGROUND CAVERN DURING EARTHQUAKE.1.MEASUREMENTS THE TUNNEL IS EXCAVATED IN TERTIARY PYROCLASTIC ROCKS,HAVING THE SIZE OF ABOUT 11M IN DIAMETER AND 60CM OF LINING CONCRETE THICKNESS,AND THE BLESTING CHARGE AMOUNT WAS 50 TO 800KG,WITH THE DISTANCEOF 150 TO 500M FROM TUNNEL.FIFTYFIVE BLASTING VIBRATION MEASUR,EMENTS HAVE BEEN CARRIED OUT BY EIGHTEEN ACCELOMETERS AND TEN DYNAMIC STRAIN METERS. 2.CHARACTERIC OF BLASTING VIBRATION WAVES ANALYSING THE PARTICLEMOTION AROUND TUNNEL,THE BLASTING VIBRATIONS ARE SEEMED TO BE THE SEQUENCE OF P-WAVE AND SH-WAVE. THE DOMINANT FREQUENCY OF RIBRATION ARE 7 TO 30 HZ,AND THE WAVE LENGTH ARE SUPPOSED TO BE 60 TO 260M FOR P-WAVE. THE MEASURED MAXIMUM ACCLERATION IS ABOUT 80 GOL. 3.VIBRATION BEHARIOR OF TUNNEL IT WAS OBTAINED FROM MEASURED WAVES THAT THE BEHARIOR OF TUNNEL AGAINST BLASTING RIBRATION MAY BE NOT SO IRREGULAR AT EACH SIDE IN THE TUNNEL. THIS WAS CONFIRMED THROUGH THE ANALYSIS COMPARING THE STRAIN AT TUNNEL LINING AND THE RELATIVE DISPLACEMENT OF BOTH SIDES IN THE TUNNEL,AS THE TIME SEQUENCE DEFORMATION. 4.COMPARISION AMONG THE MEASURED AND ANALYSIED RIBRATION DATA. THE MEASURED BLASTING VIBRATIONS WERE COMPARED WITH THE RESULTS OF NUMERICAL ANALYSIS BY DYNAMIC FINITE ELEMENT METHOD,DYNAMIC BOUNDARY ELEMENT METHOD AND RESONSE DISPLACEMENT METHOD,THE SHAPE AND PHASE OF VIBRATION WAVE OF EVERY ANALYSIS METHOD WERE SIMILAR TO THE MEASURED,BUT THE AMPLITUDS WERE A LITTLE LARGER THAN THE MEASURED ONES.

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