Three important challenges in the finite element modeling and seismic analysis of a suspension bridge are addressed in this paper. Firstly, since suspension bridges are highly nonlinear geometrically, the construction sequence should be simulated to accurately characterize the initial stresses in the structural components. For this purpose, an automated procedure that iteratively corrects the geometry of the three-dimensional finite element model of a suspension bridge using large displacement techniques has been developed. This efficient procedure saves time in model development and avoids the convergence problems that typically arise when using other methods. Secondly, since orthotropic deck structures are commonly used in long span superstructures, a technique to efficiently model this type of superstructure is explained in detail. Thirdly, a nonlinear seismic evaluation of a suspension bridge typically requires the calculation of strains in concrete and steel reinforcement. An automated procedure to compute strains in the bridge components throughout the seismic event under consideration has been developed and presented in the paper. As an example, these three techniques have been implemented for the Alfred Zampa Memorial Bridge (also known as the New Carquinez Bridge), a 1.06 km long suspension bridge, located in Vallejo, California.
Efficient Techniques in Finite Element Analysis and Seismic Evaluation of Suspension Bridges
Hassan Sedarat, Alexander Kozak, Joyce Lee, Alex Krimotat, Vince Jacob, Steve Mitchell
Seventh National Seismic Conference on Bridge and Highways (7NSC), Bridge Resilience for earthquake and other natural hazards, Oakland, May 20-22, 2013.