高墩连续刚构桥梁地震反应分析

Seismic Response Analysis of Continuous Rigid Frame Bridge with High Piers Base on Fiber Model

在通用有限元程序MSC.MARC中加入基于纤维模型编制的THUFIBER程序和三维实体单元模型分别模拟钢筋混凝土桥墩和桥梁上部结构,建立了高墩大跨连续刚构桥的有限元模型。采用汶川地震记录,针对四川境内某一实际桥梁,分析了行波效应对其地震反应的影响。结果表明:波速较小时,行波效应对墩顶的位移有利。墩底是地震分析时的危险截面,行波效应对结构反应较为复杂,在某些截面上可能加大,也可能降低,在抗震设计时,应考虑行波效应的影响。

In this paper, with the help of program THUFIBER based on the fiber model, fiber model is used to simulate bridge piers and solid element is used to simulate the superstructure in program MSC. MARC. The effects of the traveling wave on the nonlinear seismic response of the long span continuous rigid frame bridge with high piers are analyzed under 2008 Wenehuan earth- quake wave excitation. The results show that the slower the wave is, the more favorable the traveling wave effect of pier on top-displacement is. The bottom of pier is the dangerous section on which the traveling wave effection is more complicated, may be increased or lowered; Thus, traveling wave effect should be considered during the seismic design.