Seismic Performance Assessment of Offshore Reinforced Concrete Bridges Using the Force Analogy Method

In this paper, the seismic performance of offshore reinforced concrete (RC) bridges during their life cycle periods is assessed by the pushover analysis based on the concept of the force analogy method (FAM). The governing equations and implementation process of the proposed pushover method are first derived. The material nonlinearity is modeled by the local plastic mechanism, which is capable of simulating the monotonic strength hardening and softening behaviors of RC piers. The chloride ions corrosion effect for the RC bridges located in coastal areas is considered by using the deterioration model for the mechanical property of reinforcement steel. Besides, structural stability against overturning is considered by incorporating the geometric nonlinearity with the FAM. Since the initial stiffness matrices remain constant through the computation process, the advantages of the FAM, such as high efficiency and stability, are retained. A numerical example is carried out to illustrate the process of seismic performance assessment for offshore RC bridges with the FAM.