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为考虑时效及环境因素对隔震支座力学特性的影响,介绍了国外学者和规范提出的支座特性修正系数、调整系数和界限分析方法,结合中国隔震橡胶支座的特点给出了力学特性修正过程.构造了12座具有不同外型特征的连续梁桥作为研究对象,分别采用3种常用的隔震支座(即铅芯橡胶支座、高阻尼橡胶支座和超高阻尼橡胶支座),基于Open Sees地震分析计算平台建立了隔震桥梁的3维动力分析模型,通过大量的非线性动力时程分析考察了时效及环境因素对不同高度桥墩地震反应的影响程度及其在不同外型桥梁中的离散情况,还采用增量动力分析技术研究了不同地震动强度(PGA)的影响.分析结果表明:时效及环境因素对隔震桥梁地震反应的影响较大,尤其是对处于0.2~0.4g加速度峰值下隔震桥梁的较低墩的位移反应;对于采用铅芯、高阻尼和超高阻尼橡胶支座的隔震桥梁,不考虑其影响则可能低估较低墩10%、50%和100%及以上的墩顶位移需求.
In order to consider the influence of aging and environmental factors on the mechanical properties of the isolated bearings, the correction factors, adjustment coefficients and boundary analysis methods proposed by foreign scholars and norms are introduced. Combined with the characteristics of China’s rubber bearings, Characteristics correction process.A series of 12 continuous girder bridges with different exterior features are constructed as research objects, and three kinds of commonly used isolation bearings (ie, lead rubber bearing, high damping rubber bearing and ultrahigh damping rubber branch Based on the Open Sees seismic analysis and calculation platform, a 3-D dynamic analysis model of the isolated bridge was established. Through a large number of nonlinear dynamic time-history analysis, the influence degree of aging and environmental factors on the seismic responses of bridge piers at different heights was investigated. The effect of different ground motion strength (PGA) was also studied by incremental dynamic analysis.The results show that aging and environmental factors have a great influence on the seismic response of the isolated bridge, 0.2 ~ 0.4g acceleration peak under the lower pier isolation of the bridge reaction; for the use of lead-core, high damping and ultra-high damping rubber bearing isolation bridge, do not test The effects of this may underestimate the displacements at the pier tops of 10%, 50% and 100% of the lower pier.