| With the continuous and rapid development of my country’s economy,bridges,as an indispensable part of transportation,promote social progress.Offshore bridge projects are eroded by chloride salts in the marine environment for a long time,steel corrosion problems and concrete rust expansion and cracking are more common,which will greatly reduce the life of the bridge in the design service life.my country is affected by the Eurasian plate,the Indian plate,and the Philippines.The seismic zone is very active due to the influence of plate interaction,and the analysis of the seismic capacity of offshore bridges during the service period is particularly important.In this paper,a continuous beam bridge is taken as an example to establish an OPENSEES finite element model to simulate the seismic performance of bridge piers under the deterioration of offshore chloride ion erosion.Important research contents are as follows:(1)Based on the chlorine ion erosion law of reinforced Crete structure in Marine environment is as follows.,combined with Fick’s second law,the change law of material property parameters under the action of chloride ion erosion factors during service time is summarized.(2)A nonlinear finite element model of a continuous beam bridge at sea was established using OpenSees software,and the time when the steel bar began to rust was calculatede change rule of the material property parameters during the service time.(3)choose three meet in the center of the Pacific earthquake waves,the chloride ion on offshore environment degradation under three kinds of working condition of cause analysis: Only the stirrups are degraded,the longitudinal reinforcements are only degraded,and the longitudinal stirrups are degraded together.Then,the pier column is analyzed in time history to compare the response changes of the pier bottom bending moment and pier top displacement under the three working conditions.(4)Time-varying seismic vulnerability analysis is carried out on the pier columns of offshore continuous girder Bridges during the service period of 100 years,The vulnerability curve of the bridge pier component is obtained;The vulnerability surface of pier member is drawn to analyze the influence of material deterioration caused by chloride ion erosion in offshore environment on continuous girder bridge. |
