大跨度悬索桥非线性地震反应响应规律探讨

以简支单跨体系的润扬悬索桥和双塔双跨的舟山西侯门大桥为工程背景,建立了非线性动力分析有限元模型。以悬索桥的主要承重构件主缆与主塔的响应为研究对象,选取四类场地共31条地震波对不同类型悬索桥进行非线性地震反应分析。分析表明,悬索桥桥塔在不同地震作用下的位移曲线以及弯矩响应具有良好的一致性,与悬索桥桥型、地震震级无关;地震波中的长周期成分对具有长周期特性的悬索桥的结构响应有重要的影响;主缆动轴力比其恒载轴力小一个数量级,在结构的简化模型中可考虑忽略。

Discussion on Nonlinear Earthquake Reaction Response Rule of Long-span Suspension Bridge

Taking the simple-supported single-span system of Runyang Suspension Bridge and the double-pylon double-span system of Zhoushan Xihoumen Bridge as the engineering background, the article sets up the nonlinear dynamic analysis finite element model. Taking the response of the main cable and the main pylon of the main bearing members of the suspension bridge as the studying object, the article selects 31 earthquake waves in four kinds of field to implement the nonlinear earthquake reaction analysis on the different suspension bridges. The analysis shows that the displacement curves and the bending moment responses of suspension bridge pylon are good consistent under the different earthquake actions, and are not related to the suspension bridge type and the earthquake magnitude, the long-period component in the earthquake wave has the important influence on the structural response of the suspension bridge with the long-period characteristic, and the dynamic-load axial force of the main cable has one order of magnitude less than its constant-load axial force which can be neglected in the simplified model of structure.