| dc.description.abstract | Isolated bridges have been extensively used to mitigate the induced seismic forces by a shift of natural period. However, the deck displacement becomes excessively large when subjected to a ground motion with large intensity or unexpected characteristics. Such a large displacement may result in unseating of the deck. Therefore, unseating prevention devices and dampers are important particularly for isolated bridges.This study is aimed to analyze the isolated bridges with unseating prevention devices and nonlinear dampers which may exhibit nonlinear dynamic behavior under large earthquakes.
The Vector Form Intrinsic Finite Element (VFIFE), a new computational method developed by Ting et al. (2004), is adopted in this study because the VFIFE has the superior in managing the engineering problems with material nonlinearity, discontinuity, large deformation and arbitrary rigid body motions of deformable bodies. It is selected to be the analysis method in this study. However, the VFIFE is in its infant stage as compared to the conventional Finite Element. There are still a number of elements and analysis method to be developed. Some kinds of new VFIFE elements and analysis methods are herein developed for analyzing the target bridges. Through numerical simulation of examples and comparison with the Finite Element analysis, the developed elements and analysis methods are verified to be feasible and accurate. Finally, we analyze an isolated bridge to investigate the extreme functions of the isolators, columns and unseating prevention devices and to predict the collapse situation of target bridges. | en_US |