報告書番号

385013

タイトル（和文）

軟質地盤上の基礎の埋設効果に関する実験的検討（その１）起振実験・地震観測による模型基礎の埋設効果

タイトル（英文）

EXPERIMENTAL STUDY ON EMBEDMENT EFFECT OF FOUNDATION (PART 1), EMBEDMENT EFFECT OF MODEL FOUNDATION DUE TO SHAKING TEST AND EARTHQUAKE OBSERVATION

概要 （図表や脚注は「報告書全文」に掲載しております）

原子力発電所の第四紀地盤立地においては，原子炉建屋の基礎は支持地盤中に埋設される形式となるため，地震時における基礎の埋設効果を適切に評価し，建屋・地盤等の耐震設計に反映させることはきわめて重要な課題である。本研究は，起振実験・地震観測等により基礎の埋設効果を明らかにするとともに，数値解析結果を実験結果と比較することにより解析手法の妥当性を検証して，埋設効果の適切な評価法を検討することを目的とする。このうち本報告は，実地盤における模型基礎の動的挙動について検討した結果をとりまとめたものである。起振実験，地震観測から埋戻しに伴なう顕著な埋設効果，制震効果の特性を示すことが明らかとなった。ＦＥＭ解析によっても，これらの効果は比較的良好に表わすことができ，第四紀地盤における基礎の埋設効果はＦＥＭ解析手法によっても十分に評価できる見通しを得た。

概要 （英文）

EXPECTING THE INCREASING OF STABILITY DURINGEARTHQUAKE, NUCLEAR POWER REACTOR BUILDING IS TO BE EMBEDDED DEEPLY INTO IT S SUPPORTING GROUND IN CASE OF THE QUATERNARY GROUND SITING. IT IS EXCLUSIVELY IMPORTANT TO EVALUATE EMBEDMENT EFFECTS DURING EARTHQUAKE, AND TO TAKE THEM INTO ACCOUNT TO ASEISMATIC DESIGN FOR THE BUILDING AND SURROUNDING GROUND. THE PURPOSES OF THIS STUDY ARE TO EVALUATE EMBEDMENT EFFECTS FROM THE EXPERIMENTAL RESULTS OF BOTH FORCED VIBRATION TESTS AND EARTHQUAKE OBSERVATION, AND TO COMPARE NUMERICAL PROCEDURE S RESULTS WITH EXPERIMENTAL DATA IN ORDER TO CONFIRM ITS VALIDITY. THIS REPORT SPECIFICALLY DESCRIBES THE RESULT FROM DYNAMIC BE HAVIOR OF SMALL MODEL FOUNDATION (4X4X3M) SITING ON THE QUATERNARY GROUND. THE LARGER ONEIS TO BE DESCRIBED IN THE FOLLOWING REPORT. AS THE RESULT, THE FOLLOWINGS WERE MADE CLEAR. (1) THE RESPONSES ON THE FOUNDATION REMARKABLY DECREASED WITH SIDE LAYER BACK-FILL FROM FORCED VIBRATION TESTS. THESE EXPERIMENTAL PHENOMENA WERE RECOGNIZED EMBEDMENT EFFECT, AND HALF SPACE ELASTIC THEORY, ESPECIALLY ON SIDE LAYER DAMPING CONSTANTS, COMPARATIVELYILLUSTRATED THIS EFFECT.(2) FROM EARTHQUAKE OBSERVATION, THE TRANSFER FUNCTION ON THE FOUNDATION IN NON-BACK FILL CASE INDICATED THE SAME DOMINANT FREQUENCY OBTAINED BY FORCED VIBRATION TESTS. THE OTHER HAND, FROM THE ANLYSIS OF SPECTRAL RATIO BETWEEN THE FOUNDATION AND GROUND IN FULL-BACK-FILL CASE, THE AMPLITUDE DECREASED AT HIGH FREQUENCY RANGE. (3)THE RESONANCE CURVES OBTAINED FROM NUMERICAL PROCEDURE BY FEM NAMED TB3DI AGREED FAIRLY WELL WITH THOSE FROM FORCED VIBRATION TESTS BOTH ON THE FOUNDATION. SO, THE AUTHORS CONCLUDED THIS FEM ANALYSIS HAD ENOUGH USEFULNESS TO ESTIMATE EMBEDMENT EFFECT ON THE QUATERNARY GROUND.

報告者

キーワード