考虑悬臂结构转动的开启桥桥面铺装动响应分析

Dynamic Response Analysis of Deck Pavement on Bascule Bridge Considering the Rotation of Cantilever Structure

为分析开启桥在转动开启过程中桥面铺装的动力响应,以天津响螺湾海河开启桥为研究对象,利用有限元方法建立包含转轴的1/4开启桥精细模型,对开启桥变速开启全过程进行数值模拟,追踪钢桥面铺装体系在不同开启角度和不同开启速度时的动力响应,并与简化转轴的开启桥模型分析结果进行对比。结果表明:在变速开启过程中,铺装层层间剪应力在横向和纵向均呈现出明显的应力集中现象,铺装结构的拉应力和铺装层层间剪应力均随着开启角度的增大而增加,在开启角度最大时达到最大值,峰值出现的纵桥向位置均为悬臂结构的自由端;建立精细化转轴的模型转动开启过程中的动态应力响应比简化转轴静态应力结果大15%~20%;因此,建议在设计阶段开启桥铺装体系复合结构时考虑采用精细化转轴模型。

In order to analyze the dynamic response of deck pavement in the process of rotating opening of bascule bridge,taking the Tianjin Xiangluowan Haihe Bridge as the research object,this study established a 1/4 fine finite element model of bascule bridge including the rotating shaft.The dynamic simulation of the variable speed opening process of the bascule bridge was carried out,and the dynamic responses of steel bridge deck pavement system at different opening angles and different opening speeds were tracked.The results were compared with the analysis results of the simplified bascule bridge model.which show that the stress concentration of interlaminar shear stress of pavement occurs both in transverse and longitudinal directions during variable speed opening.The tensile stress and interlaminar shear stress of pavement increase with the increase of the opening angle,and reach the maximum at the maximum opening angle.The longitudinal position of the peak is the free end of the structure,and the dynamic stress response of a refined rotating shaft model during its opening is 15%~20%larger than that of a simplified rotating shaft model.Therefore,it is suggested that the refined rotating shaft model should be adopted in the composite structure of the open bridge pavement system at the design stage.