桥梁中抗震限位装置设计方法的研究

为防止桥梁上部结构在地震中发生落梁破坏,通常在伸缩缝处安装限位装置。在调查影响伸缩缝处相邻梁体相对位移因素的基础上,根据线性化模型提出一种限位装置设计方法。该方法既考虑了相邻桥跨不同向振动的动力特性,又考虑了相邻梁体间碰撞对相对位移的影响。运用替代结构法考虑墩柱的弹塑性,使用考虑碰撞效应的相对位移反应谱考虑碰撞对相对位移的影响。通过参数研究对提出的限位装置设计方法的可靠性进行验证,并通过与已有的限位装置设计方法相比,评估了所提出的限位装置设计方法的限位效果。与已有的设计方法相比,本文提出的限位装置设计方法与非线性时程分析结果的相关性更好。

A study on the design method of seismic restrainers for bridges

Seismic restrainers are often needed at expansion joints of bridges to prevent the superstructures from falling off during earthquakes.Factors affecting the relative displacement between bridge segments at expansion joints are investigated,and a design procedure for restrainers,based on a linearized model,is developed.This restrainer design procedure not only takes into consideration the dynamic characteristic out-of-phase motion of adjacent bridge segments,but also the effect on the relative displacement due to impact between bridge segments.Inelastic behavior of piers is represented by using the substitute structure method,and the effect of impact on relative displacement is considered by using the relative displacement response spectra with impact effect.Reliability of the proposed restrainer design procedure is validated through parametric studies,and the effect of this restrainer design procedure in limiting relative displacement is assessed by comparing with existing restrainer design procedures.The results of the studies indicate that,comparing with existing restrainer design procedures,the restrainers designed from using proposed procedure are more consistent with those from nonlinear time-history analysis.