Bridges: Nonlinear Analyses, Probability Theory and Optimization Theory

Cosic M., Folic R., Folic B.: Bridges: Nonlinear Analyses, Probability Theory and Optimization Theory (poster)

The poster shows a multidisciplinary approach to the assessment of seismic performances based on the Performance-Based Earthquake Engineering (PBEE), taking into account the multi-criteria optimization theory in analyzing the priority methods for bridge rehabilitation/strengthening. One bridge model was subjected to nonlinear static pushover analyses (NSPA), target displacement analyses using the spectrum capacity method (CSM), vulnerability analyses, and reliability analyses, while for a damaged bridge, in addition to be considered using the above methods, was also analyzed using the VIKOR method of multi-criteria optimization.

Soil-Pile-Pier Interaction

Cosic M., Folic B., Folic R., Susic N.: Soil-Pile-Pier Interaction (presentation)

The purpose of this presentation is to show the methodology for performance-based seismic evaluation of soil-pile-bridge pier interaction using the incremental nonlinear dynamic analysis (INDA). The INDA analysis was post processed separately for the pier and for the pile, so that the constructed PGA=f(DR) curves are in the capacitive domain. For these curves the authors identified the IO, CP and GI performance levels, while the regression analyses were conducted based on the specific DR and PGA parameters. Fragility curves were constructed based on the solutions of regression analysis and the probability theory of log-normal distribution. Based on the results of fragility analysis, reliability curves were also constructed.

Deciding the Order of Interventions on the Structure of Reinforced Concrete (RC) Bridges

Folic R., Cosic M., Folic B.: Deciding the Order of Interventions on the Structure of Reinforced Concrete (RC) Bridges (presentation)

A multitude of existing bridges fail to meet the criteria of seismic resistance, as designed according to inadequate regulations, which eventually led to the reduction in their resistance. This practice requires interventions (rehabilitation or strengthening) conducted on their structure, which in turn requires developing methods of assessment of seismic performances of existing reinforced concrete (RC) girder bridges. Due to budget constrains it is impossible to strengthen all the bridges, so that a list of priorities is necessary to be drawn. The rank of a specific bridge in this list is stated by the importance of the road, age of the bridge, technical regulations according to which the bridge was designed and the condition of vital support elements. Ranking requires conducting multi-criteria optimization. This paper is focused on overpass, which is used to demonstrate the developed methodology.