Filipov et al. 2011
The work presented in this paper is an investigation of prescribed sequential fusing of specific components of bridge systems such that critical components can maintain their integrity after an earthquake. The examined earthquake resisting system is an extension of common bridge design in high seismic regions. The fuse mechanism is implemented at the interface between the substructure and superstructure, which remain elastic. The goal is to study the global bridge system quasi-isolated response when subjected to large seismic motions.
System Concept
The bridge models were analyzed using the open source, nonlinear seismic analysis program OpenSees. Elements in the bridge superstructure were modeled as linear elastic and the girders were modeled as linear beam-column elements. The deck was modeled using four-node shell elements with linear elastic behavior and low-profile fixed bearings were implemented at one of the intermediate pier, while Type I or Type II elastomeric expansion bearing were used at the other pier and abutments.
Analytical Study
Using the OpenSees program, a preliminary parametric study using transient nonlinear dynamic analysis was performed. The base bridge model was simulated using a synthetic earthquake record generated for Paducah, KY. A baseline set of analyses were completed using strong ground motions in the transverse direction at different intensities. Initial results show that the bearing friction force has a large influence on the superstructure displacement in the transverse direction. Also, the abutment back wall tends to limit longitudinal displacements.
Reference
Filipov, E. T., Hajjar, J. F., Steelman, J. S., Fahnestock, L. A., LaFave, J. M., and Foutch D. A. (2011). “Computational Analyses of Quasi-Isolated Bridges with Fusing Bearing Components,” Proceedings of the Structures Congress 2011, Las Vegas, NV, April 14-16.