報告書番号

U97020

タイトル（和文）

台湾・花蓮地点における大規模耐震実証試験研究－根入れされた大規模模型建屋の起振時・地震時挙動のシミュレーション解析－

タイトル（英文）

THE HUALIEN LARGE-SCALE SEISMIC TEST FOR SOIL-STRUCTURE INTERACTION RESEARCH -RESPONSE ANALYSIS OF EMBEDDED STRUCTURE DURING FORCED VIBRATION TESTS AND DURING EARTHQUAKES-

概要 （図表や脚注は「報告書全文」に掲載しております）

砂礫地盤に根入れされた大型模型建屋の埋め戻し前・後の強制振動試験説きの予測・修正解析，地震時建屋挙動の予測・修正解析を通じて，以下の諸点が明らかとなった；（１）埋め戻し前強制振動試験の予測解析では一次共振振動数の予測値は試験値よりも高かったが，加振位置の違いによる応答曲線の違いなど，本手法の適用性も示された。また建設過程進展に伴う砂礫層の剛性変化を地盤モデルに組み込んだ解析では試験値との良好な一致を得，こうした剛性変化を適切に地盤モデルに組み込むことの重要性が示された。（２）自由地盤面での地震観測波形を与えた解析との対比により，当所が提案した「共通地盤モデル」における自由地盤モデルの妥当性が示された。（３）埋め戻し後の建屋強制振動試験の「修正解析」を通じて作成された「修正地盤モデル」を用いた地震応答解析は，「共通地盤モデル」を用いた解析と大差なく，埋め戻し部のＶｓは地震応答に際しては強制振動試験の時ほどには影響は強くないことが示された。

概要 （英文）

PREDICTIVE AND CORRELATIVE ANALYSES OF FORCED VIBRATION TESTS OF A LARGE-SCALE MODEL STRUCTURE EMBEDDED IN A GRAVELLY LAYER BEFORE AND AFTER BACKFILL WERE PERFORMED. ALSO SIMILAR ANALYSES OF THE SAME STRUCTURE SUBJECTED TO EARTHQUAKES WERE PERFOMED. THE RESULTS WERE AS FOLLOWS: (1)THE FUNDAMENTAL SYSTEM FREQUENCY OF THE FORCEDVIBRATION TEST BEFORE BACKFILL PREDICTED BY THE 3D FEM COMPLEX DYNAMICRESPONSE ANALYSIS CODE (TB3D) WAS 9% HIGHER THAN THE TEST RESULT. PREDICTIVE ANALYSIS ALSO SHOWED THE APPLICABILITY OF TB3D, GETTING WELL PREDICTED RESULT OF THE BASIC CHARACTERISTICS OF THE RESPONSE DIFFERENCE APPEARING IN THE TESTS DUE TO THE EXCITATION POSITION DIFFERENCE IN THE HORIZONTAL EXCITATION CASES, GATTING WELL SIMULATED RESULT OF THE TEST WHERE PHASE LAG FREQUENCY RESPONSE CURVE IS CONVEX FUNCTION DOWNWARD, AND SO ON. ANALYSIS BY THE GROUND MODEL INCORPORATING THE VS CHANGE FOLLOWING THE CONSTRUCTION STAGE SHOWED GOOD FUNDAMENTAL SYSTEM FREQUENCY AGREEMENT WITH THE TEST, INDICATING THE IMPORTANCE OF APPOPRIATE INCORPORATION OF SUCH VS CHANGE INTO THE GROUND MODEL. (2)GIVING THE OBSERVED FREE FIELD GROUND SURFACE MOTION A ONE-DIMENSIONAL DECONVOLUTION PROCEDURE GAVE EXCELLENT AGREEMENT WITH THE OBSERVATIONS, INDICATING THE VALIDITY OF THE FREE FIELD SOIL MODEL IN THE UNIFIED MODEL PROPOSED BY CRIEPI. (3)SEISMIC RESPONSE ANALYSIS USING BEST CORRELATED MODEL FOR THE FORCED VIBRATION TEST AFTER BACKFILL GAVE SLIGHTLY BETTER AGREEMENT WITH THE OBSERVATIONS THAN USING THE UNIFIELD MODEL, BUT BOTH ANALYSES AGREED FAIRLY WELL WITH THE OBSERVATIONS, INDICATING THAT THE VS OF THE BACKFILL DOES NOT AFFECT THE SEISMIC RESPONSE AS MUCH AS DURING FORCED VIBRATION TESTS.

報告者

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