A Work Paper on -Structural Behaviour of Salts around the Pushover RC Bridges

There are presently no comprehensive guidelines to assist the practicing structural engineer to evaluate existing bridges and suggest design and retrofit schemes. In order to address this problem, the aims of the present structure was to carry out a seismic evaluation case study for an existing RC bridge using nonlinear static (pushover) analyze. Bridges extends horizontally with its two ends restrained and that makes the dynamic characteristics of bridges different from building. Modal analyze of a 3D bridge model reveals that it has many closely-spaced modes. Participating mass ratio for the higher modes is very high. Therefore, pushover analyze with single load pattern may not yield correct results for a bridge model. A 12-span existing RC bridge was selected for the case study. Standard pushover analyze using FEMA 356 displacement coefficient method and an improved upper bound pushover analyze method were used to analyse the building. Some of the analyze parameters were suitably modified to use in a bridge structure. The evaluation results presented here shows that the selected bridge does not have the capacity to meet any of the desired performance level.