３次元地盤環境振動予測システムの開発

幹線道路や鉄道に隣接して、振動を嫌う最先端施設を建設する要求が増加してきている。これらの施設の要求性能を満たすためには、建物環境や内部に設置される超精密機器の厳しい振動許容値を満たす必要がある。交通機関等の加振源から地盤を介して構造物に伝搬する振動をより精度良く予測し、最適な振動低減対策を行なうためには、精度の高い3次元地盤-構造物連成振動解析が必要となる。そこで、構造物または近傍地盤については3次元FEMで、遠方地盤については効率的にモデル化できる3次元薄層要素法を用いてモデル化し、それらを結合させた地盤環境振動予測システムを構築した。

3-Dimensional Predictive Analyses of Ground Vibrations produced by Machines and Traffics

The construction of high-tech facilities that must be protected against vibrations caused by main roads and railways has been in great demand. In order to satisfy the requirement of performance of these facilities, it is necessary to control the vibrations within the allowable limit being strict for precision instruments in buildings. This implies necessity for development of 3-dimensional dynamic soil-structure analysis that makes it possible to accurately predict the vibrations transmitting from sources to structures via soils, and to apply the most suitable measures for reduction of vibrations. Therefore, we have developed the analysis technique that combines 3-D FEM with thin layer method to predict the ground vibrations produced by traffics, machines and construction operations. Hence, 3-D FE and thin layer models represent near-field including structures and far-field, respectively