海底地震动作用下近海桥梁地震响应研究

Seismic response of offshore bridges under seabed seismic motion

以某近海大桥引桥段连续梁桥为工程背景,建立考虑海底地震动特性和腐蚀效应的近海桥梁地震反应分析模型。采用增量动力分析方法分析腐蚀效应以及海底地震动作用对近海桥梁地震响应的影响。研究结果表明:腐蚀效应与海底地震动作用都会不同程度影响近海桥梁结构的抗震性能。其中:腐蚀效应会增大近海桥梁的破坏指标,降低最大墩底剪力和弯矩值,从而降低桥梁的抗震性能;海底地震动作用会增大近海桥梁的破坏指标及最大墩底剪力、弯矩值;在2种因素耦合作用下,桥梁的抗震性能将会进一步降低。

The offshore bridge′s approach sectional continuous girder bridge is set as an engineering background of this study,the model considers seabed seismic motion and corrosion influence.The seismic response analysis of offshore bridgewith corrosion under the seabed seismic motion is conducted by using incremental dynamic analysis(IDA)method.The research results show that:The corrosion effectand the seabed seismic motion will affect the seismic performance of the offshore bridge to varying degrees.Among them,the corrosion effect will increase the damage index of the offshore bridge,reduce the maximum values of the pier bottom shear and bending moment,and thus reduce the seismic performance of the bridge;The seabed seismic motion will increase the damage index of the offshore bridge and the maximum values of the pier bottom shear and bending moment;Under the coupling of seabed seismic motion and corrosion,the seismic performance of the bridge will be further reduced.