横系梁对双柱墩及其基础地震反应的影响

Effects of the Link Beam on Seismic Responses of the Double-column Pier and its Foundation

基于OpenSees软件,研究系梁对无盖梁双柱墩及其基础的地震反应的影响。以桥墩高度、系梁数量和系梁刚度为基本参数,首先采用弹性单元建立无系梁双柱墩和系梁双柱墩模型进行时程反应对比分析,研究弹性系梁对地震作用下双柱墩墩底弯矩、基础剪力和弯矩的影响。然后利用弹塑性纤维单元建立系梁模型,研究系梁屈服耗能对减小双柱墩及其基础地震反应的作用。结果表明,增设横系梁后可以显著减小墩柱的地震反应,但会使得基础的反应稍有增加;系梁屈服会使墩柱底的弯矩有所增加,但对基础的地震反应是有利的。

To explore the effects of link beam on seismic performances of double-column piers without cap beams as well as its foundations,an OpenSees model was constructed.First,the elastic element was used to construct double-column pier model and link beam double-column piers model,considering the height of piers,the number and stiffness of link beams.Comparative analyses were implemented to study the influences of elastic link beam on the moment of the pier bottom and foundation for the double-column pier that is subjected to earthquakes.The link beam model with elastic-plastic fiber element was constructed to study the energy dissipation contribution of the link beam on reducing seismic responses.The results reveal that the link beam contributes to reduce pier seismic responses,but it increases the seismic response of foundation.When the link beam works in the plastic state,it increases the pier moment,but it has positive effects on the foundation seismic behaviors.