報告書番号

382009

タイトル（和文）

地盤－構造物連成系の３次元振動応答解析プログラムの開発と検証

タイトル（英文）

DEVELOPMENT OF A COMPUTER PROGRAM FOR 3-D COMPLEX RESPONSE ANALYSIS OF SOIL-STRUCTURE INTERACTION PROBLEMS WITH TRANSMITTING BOUNDARIES

概要 （図表や脚注は「報告書全文」に掲載しております）

動的相互作用問題をＦＥＭによって解析する場合，逸散波動の吸収を図るため，伝達境界手法を併用することが多くなってきた。同手法は従来，２次元平面歪ないし軸対称条件で定式化されており，基盤を前提している。著者らは円筒座標系で展開された伝達境界の内部に，軸対称部と共に直交座標系で展開された３次元部を含みうる連成系振動解析コード（ＴＢ３Ｄ）を開発した。ＴＢ３Ｄではモデル底面に粘性境界を付与して基盤を除去できる。本報告ではＴＢ３Ｄの概要を述べ，次のように理論解，実験例との対比を行ってその妥当性を検証した。１）成層地盤仮定の解析で表面波の分散性を良好に模擬できた。２）弾性層上の長方形基礎の水平加振時応答解を求め，基盤のある場合，半無限地盤の場合とも，理論解との良好な合致を得た。３）原子炉建屋基礎－地盤系の水平加振実験例の模擬を行い，基礎水平動のみならず，上下動に関しても実験値との良好な一致を得た。

概要 （英文）

SOIL-STRUCTURE INTERACTION IS ONE OF THE MAIN SUBJECTS IN EARTHQUAKE ENGINEERING. FEM IS OFTEN USED TO ANALYZE SOIL-STURE INTERACTIONS, BUT THE PROBLEM IS HOW TO SET NUMERICAL BOUNDARIESIN THE GROUND WHICH IS SEMI-INFINITE. TRANSMITTING BOUNDARY METHOD HASBEEN PROPOSED TO SETTLE THESE PROBLEMS WHICH HAS BEEN FORMULATED IN PLANE STAIN CONDITION OR IN AXISYMMETRIC CONDITION HITHERTO. IN THE METHOD DEVELOPED BY THE AUTHORS, 3-D REGION IN WHICH RECTANGULAR CO-ORDINATES ARE USED IS ABLE TO BE INTRODUCED AMONG THE AXISYMMETRIC REGION WHICHCONTAINS THE REGULAR ZONE WITH TRANSMITTING BOUNDARIES IN WHICH CYLINDRICAL CO-ORDINATES ARE USED. THE NEWLY-DEVELOPED COMPUTER CODE WITH THEMETHOD MENTIONED ABOVE IS NAMED TB3D-1. IN THIS REPORT,THE OUTLINE OF TB3D-1 IS GIVEN FIRST.THEN,THE METHOD IS APPLIED TO THE PROBLEMS WHICH HAVE THEORETICAL SOLUTIONS. AMONG THE THEORETICAL PROBLEMS, DISPERSIVE PROPERTIES OF STRATIFIED ELASTIC MEDIA ARE SIMULATED FIRST.THEN, THE DYNAMICAL BEHAVIOR OF THE RIGID FOUN-DATION ON THE ELASTIC UNIFORM STRATUM IN THE HORIZONTAL EXCITATION IS SOLVED. IT HAS TWO CASES:ONE IS THE CASE WITH RIGID BASE, AND THE OTHER IS WITHOUT RIGID BASE. IN BOTH CASE,THE NUMERICAL RESULTS BY THIS METHOD COINCIDE WELL WITH THEORETICAL SOLUTIONS. LASTLY, THE DYNAMICAL BEHAVIORS OF THE ACTUAL R/B FOUNDATION OF THE NUCLEAR POWER PLANT UNDER HORIZONTAL EXCITATION ARE SIMULATED. WEALSO OBTAINED GOOD AGREEMENTS BETWEEN NUMERICAL AND EXPERI-MENTAL RESULTS. THROUGH THESE SIMULATIONS, COMPUTER CODE TB3D-1 IS CERTIFIED TO HAVE ENOUGH EFFECTIVENESS AND USEFULNESS.

報告者

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