| dc.description.abstract | In the past two decades, a number of near-fault ground motions have been recorded in major earthquakes, such as the 1999 Chi-Chi earthquake. Near-fault ground motions comprise long-period pulses, which is unique as compared to far-fault ground motions. Numbers of bridges along the Chelungpu fault suffered damage, even collapsed, during the Chi-Chi earthquake. Those can be attributed to not only the strong ground motions but also ground dislocation.
The Vector Form Intrinsic Finite Element (VFIFE) is superior in managing the engineering problems with material nonlinearity, discontinuity, large deformation, large displacement and arbitrary rigid body motions of deformable bodies. The VFIFE is thus selected to be the 3-D analysis method in this study. A three-span-continuous bridge is analyzed to predict the failure situation under 3-D near-fault ground motions with dislocation. Through a serious of parametric studies, the failure modes are demonstrated for bridges. Besides, the failure mechanism of bearing system is clarified so as to compare the feasibility of different bearing system.
And in order to analyze the real condition of the section, this study is aimed to develop the new model of Fiber Element that using stress-strain relation in plastic hinge zone to simulate high-degree nonlinear behavior of bridges by strong motion. Implicit time integration method (Newmark-β) is adopted to renew the iteration type of Fiber Element Method to calculate the element internal force. Finally, this study analyzes a five-span-continuous isolated bridge to investigate the extreme functions of the columns and unseating prevention devices between Fiber Element and Bilinear Spring, and predict the collapse situation of the target bridge. | en_US |