Seismic Fragility Analysis of Bridge Piers Based on Lowcycle Fatigue Life of Reinfrocing Steel

Abstract:

A nonlinear fiber beamcolumn element was used to simulate quasistatic tests of circular concrete bridge piers reinforced with HRB335 and HRB500E longitudinal bars based on CoffinManson lowcycle fatigue damage model for reinforcing steel. The effects of lowcycle fatigue damage on the strength degradation of reinforcing steel and reinforced concrete specimens were studied. In order to further verify the effect of lowcycle fatigue of reinforcing steel on the cumulative damage of reinforced concrete specimens, two quasistatic tests proposed by Takemura and Kunnath with different loading modes were conducted. The results indicate that, the fiber beamcolumn element could simulate the cumulative damage and strength degradation of reinforced concrete columns under different loading modes when considering the lowcycle fatigue of reinforcing steel on material level by using CoffinManson model.

Key words:reinforced concrete; bridge piers; lowcycle fatigue; cumulative damage; strength degradation; fiber beamcolumn element