In order to analyze the influence of material deterioration on the seismic performance of bridge piers,based on the chloride ion erosion mechanism and the steel bar corrosion principle,the mechanical property degradation law of concrete and steel bars is ob-tained.According to the seismic vulnerability principle,the damage index of bridge piers is determined through the displacement ductil-ity ratio,and the seismic vulnerability model of bridge piers is constructed considering material deterioration.Taking Baiqihu Bridge as an engineering example,36 seismic waves conforming to site conditions are selected to analyze the seismic response requirements of piers considering material property degradation.Based on this,the seismic vulnerability curves of piers under different service life are established.The results show that the exceedance probability of the pier reaching each damage state increases significantly with longer service time.The exceedance probability difference between minor damage,moderate damage and severe damage is significantly smaller than that between severe damage and complete damage,indicating that the ductility of piers between minor damage,moderate damage and severe damage is smaller than that between severe damage and complete damage.The interval of seismic vulnerability curves be-tween 51 and 75 years of service is significantly greater than that between 0 to 25 years of service,26 to 50 years and 76 to 100 years of service,that is,the exceedance probability of bridge piers during 51 to 75 years of service increases significantly,indicating that cor-rosion at this stage leads to a significant decrease in the mechanical properties of steel bars and concrete,resulting in a significant de-cline in seismic performance.
关键词
桥墩/材料性能/劣化/地震易损性/服役年限
Key words
bridge pier/material properties/deteriorate/seismic vulnerability/service life
维普
万方数据