基于多点激励的大跨径高墩连续刚构桥行波效应分析

依托跨径布置为(68+128+68)m的某铁路预应力混凝土连续刚构桥,采用通用有限元软件建立空间动力模型研究了该桥的动力特性,对该桥在一致激励和行波效应下的内力和位移进行了对比分析。多点激励作用下的位移结果比一致激励作用下的结果大,并且随着波速的增大而逐渐逼近一致;行波效应对主墩墩顶和墩底截面的弯矩和剪力的影响明显。研究成果可为大跨径高墩铁路连续刚构桥的抗震设计提供参考。

Analysis on Traveling Wave Effect of Long-span Continuous Rigid Frame Bridge with High Piers Based on Multi-Support Excitation

Based on a railway pre-stressed concrete continuous rigid frame bridge with span arrangement of (68+128+68)m, a spatial dynamic model is established by finite element software to study the dynamic characteristics of the bridge. The internal forces and displacements of the continuous rigid frame bridge under the uniform excitation as well as the traveling wave effect are analyzed. The displacement results of the multi-support excitation is larger than those of the uniform excitation and the results of the bridge is reduced gradually with the increase of the seismic wave velocity. The traveling wave effect has significant impact on the moment and shear of the pier's top and bottom section. The research results of this paper can provide reference for seismic design of long-span railway continuous rigid frame bridge with high piers.