设缝双肢墩曲线刚构桥抗震性能研究

Research on seismic performance of curved rigid frame bridge with double-column piers with gap

双肢墩和整体式桥墩在刚构桥上使用较多,但整体墩多用于高墩,双肢墩柔性好但布置较为复杂。介绍了一种新型设缝双肢墩,并通过建立ANSYS有限元模型,分析比较4种结构形式:连续曲线梁桥、设缝双肢墩曲线刚构桥、双肢墩曲线刚构桥、整体墩曲线刚构桥的动力特性,并通过反应谱法对其进行抗震性能评估。结果表明:4种结构形式的低阶振型主要是桥墩变形,桥墩是较为薄弱的构件;采用设缝双肢墩与双肢墩的刚构桥自振频率和振型结果较为接近;两者的墩底剪力均略大于连续梁,远小于整体墩刚构桥。可见,设缝双肢墩的抗震性能与双肢墩接近,但外观上更简洁美观,适合用于曲线刚构桥上。

Double-column piers and single-column pier are widely used in rigid frame bridges,but single-column pier is mostly used in the case of higher pier.There is better flexibility of double-column piers,but which is more complex to construct.In this paper,a new kind of double-pier with gap is proposed,and four finite element models are established by ANSYS to investigate the dynamic characteristics of them,such as:continuous curved beam bridge,curved rigid frame bridge with double-column piers with gap,curved rigid frame bridge with double-column piers and curved rigid frame bridge with single-column pier.Then the seismic performance evaluations are carried out.The results show that:the pier deformation is mainly occurred at the case of low-order vibration mode of all of the four structural forms,so the piers are relatively weak components,the results of self-vibration frequency and modes of rigid frame bridge with double-column piers with gap and double-column piers are similar,the shear at the bottom section of pier of the both are slightly larger than that of continuous beam bridge,far less than that of single-column pier rigid frame bridge.It can be seen that the seismic performance of double piers with gap is close to that of double piers,but the appearance is more concise and beautiful than the latter one,so it is appropriate to be used in curved rigid frame bridge.