Seismic Toughness Analysis of Bridge Considering Chloride Ion Erosion and Scouring Effect
In order to analyze the seismic toughness of bridge under chloride ion erosion and scouring effect,the degradation law of material properties under chloride ion erosion was obtained according to the chloride ion erosion mechanism,and the calculation model of pier scouring depth was constructed.Based on the seismic vulnerability theory,the seismic toughness analysis method of bridge was proposed.Taking a river-crossing girder bridge in China as an engineering example,the seismic vulnerability and seismic toughness of the bridge piers under chloride ion erosion,scouring effect and combined action of chloride ion erosion and scouring effect are analyzed respectively.The research shows that:with the increase of service life,the scouring depth of pier increases,the degree of chloride ion erosion of pier increases,and the overrunning probability of pier under different damage conditions increases.The impact of scouring effect on seismic vulnerability of pier is more serious than that of chloride ion erosion.The overtaking probability of pier considering chloride ion erosion and scouring effect is slightly lower than that considering only scouring effect.With the increase of earthquake intensity(PGA),the seismic toughness of pier decreases continuously,and when PGA is small,the seismic toughness decreases rapidly,and when PGA is large,the seismic toughness tends to be flat,and the deceleration is first fast and then slow,which indicates that the seismic toughness of pier has reached the limit under the action of large earthquake.With the increase of bridge service time,the seismic toughness of piers only under the consideration of scouring effect,chloride ion erosion and their combined action decreases to varying degrees.The seismic toughness of piers under the scouring effect is greater than that under the consideration of chloride ion erosion,and the seismic toughness of piers under the combined action is smaller than that under the consideration of scouring effect or chloride ion erosion.
bridgesseismic toughnesschloride ion erosionscouring effectvulnerability
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