现行桥梁抗震设计规范对超长多跨连续梁桥的适用性分析

Applicability of the Existing Seismic Design Code for the Ultra Long Multispan Continuous Bridges

本文以苏通大桥南引桥为例,按照现行《公路工程抗震设计规范》提供的相关计算公式与有限元的计算结果进行比较分析,探讨了梁桥纵横向相邻桥跨之间的耦联作用。比较结果表明:对于纵桥向,两者反应谱的计算结果相差不大。时程结果表明,如果不考虑滑动摩擦支座的滞回耗能作用,两者的计算结果误差较大;对于横桥向,非均匀刚度的连续梁桥相邻跨之间的耦联性较大,建议今后采用规范对于明显非均匀刚度连续梁桥的横桥向进行地震反应分析时应该予以重视。

Taking the south approach of the SUTONG Bridge as example, the interaction of the adjacent spans in the longitudinal and lateral direction is discussed in this paper, comparing the results according to Specifications of Earthquake Resistant Design for Highway Engineering with the results from FEM analysis. The results indicate that in longitudinal direction the results of the two methods are almost the same based on response spectrum analysis, but the discrepancy of the two methods through time-history analysis are consequential when the ability of energy dissipated of friction bearing is not taken into account. Meanwhile, in lateral direction, much more attention should be paid to the seismic analysis of the inhomogeneous rigidity＇s continuous bridges due to the remarkable interaction between the adjacent spans.