重要文化財法華経寺五重塔の地震•風応答観測とその考察: 解析モデルによる地震·風応答計算と風観測 その2

摘要

前報その1では法華経寺の振動観測システムと画像観測システムを説明し、観測された振動特性と、ほぼ2年間の長期連続変形観測を示し、2011年東北地方太平洋沖地震の観測結果について述べた。その2では心柱を含めたモード解析を行い、固有振動数を計算し塔身との連成を検討した。%Motion behaviors of the national heritage five story wooden pagoda at Hokekyouji temple are observed from 2007. Continuing part 1,modal and response analyses for the pagoda are conducted. The model is made by using the beam vibration modes. Response analyses are carried out for both 3/11 earthquake and strong wind. As results of linear numerical calculations to strong earthquake motion and strong wind, the damping about 5%-10% would be agreed with observed response data. Modal analysis results showed the possibility of resonance between a pagoda frame and center column. However, in actual pagoda, it would be difficult to expect dynamic damper effects because of irregularities of pagoda structure.