Seismic Performance of RC Bridge Pier Based on Shear Numerical Analysis Model under Chloride Ion Erosion
Since near-sea bridges are located in the environments with high concentrations of chloride ions,the seismic performance of bridge piers under chloride ion erosion have been of great concern.In this paper,the reinforced concrete(RC)bridge pier subjected to chloride ion action are studied,and the material parameters under different corrosion levels are calculated by combining Fick's second law.With the help of OpenSees platform,combined with Leborgne shear strength degradation numerical analysis model,a bending-shear numerical analysis model of bridge pier under chloride ion erosion is established by calculating the rotation angle θf of plastic hinge area at the bottom of the pier during shear failure to monitor the moment of shear failure.Further,the accuracy of the model is verified by being compared with the existing quasi-static test data of corrosion RC pier column.Taking a harbor bridge in the north as the engineering background,we established a numerical analysis model,and selected seven near-fault ground motions of the 1999 Chi-Chi earthquake in Taiwan,China for dynamic time-history analysis.The results show that with the erosion of chloride ion,the performance of RC materials deteriorates seriously,the demand for seismic displacement of the bridge piers gradually increases during the service period,and the seismic performance decreases.Therefore it is necessary to consider the chloride ion erosion in the design of offshore bridge structures.
seismic performance of bridgeschloride ion erosionnumerical simulationOpenSees