解析手法の違いが津波浸水計算結果に及ぼす影響の評価

摘要

本稿では鉄道の津波対策の支援を目指して，石卷駅周辺を含む領域をモデル領域に選定し，2次元および3次元の津波解析手法を用いて東北地方太平洋沖地震による津波の浸水深の計算を行った。その結果を以下にまとめる。地形モデルを詳細地形モデルとした場合，2次元計算と3次元計算の結果から求めた幾何平均および幾何偏差の値に大きな違いはなかつた。%In order to ensure the safety of railways against tsunami hazards, we estimated the tsunami flood deptn in the model area by 2-dimensional tsunami analysis method and 3-dimensional one. In the case of using the detailed terrain model, the geometric means and the geometric deviation values respectively obtained by the 2-dimensional analysis method and 3-dimensional one were not significantly different. However there is the difference between the distribution of the maximum flooding depth by the 2-dimensional analysis and that by the 3-dimensional analysis. In the case of the tsunami source model in which the fault slip was adjusted amount to 70%, the result of 2-dimension analysis did not show any occurrence of overflowing the embankment, but the result of 3-dimension analysis showed an occurrence of overflowing the embankment.