转体拱桥混凝土球铰设计参数优化研究

Optimization study of concrete ball-hinge design parameters for transverse arch bridges

混凝土球铰的设计参数对于转体拱桥的结构应力分布具有十分重要的影响。以黄梅龙坪拱桥为研究对象,建立混凝土球铰结构的局部精细化有限元模型,探究曲率半径、支承半径以及下球铰露出高度等参数对球铰接触应力的影响,并基于响应面法对其影响性进行量化评价。结果表明:随着曲率半径的增大,球铰的最大接触应力有所增大且分布不均;随着支承半径的增加,球铰的接触应力不断减小且分布更加均匀;当球铰露出高度大于15 cm时,球铰接触应力沿径向变化幅度较大,不利于转体施工安全顺利地进行,实际施工时球铰露出高度应控制在5~15 cm。基于响应面法对比分析发现,上述因素对于球铰接触应力的影响程度大小排序为支承半径、露出高度、曲率半径。

The design parameters of concrete ball hinges have a very important influence on the structural stress distribution of a rotating arch bridge.Taking the Longping Arch Bridge in Huangmei as the engineering background,a locally refined finite element model of the concrete ball-hinge structure was established to investigate the influence of parameters such as radius of curvature,radius of support,and height of the lower ball-hinge on the contact stress of the ball-hinge,and its influence was quantitatively evaluated based on the response surface method.The results show that the maximum contact stress of the ball hinge increases with the increase of the radius of curvature and is unevenly distributed,while that decreases with the increase of the radius of support and is more evenly distributed.When the height of the ball hinge is more than 15 cm,the contact stress of the ball hinge varies greatly in the radial direction,which is not conducive to the safe and smooth progress of the rotating construction,and the height of the ball hinge should be controlled in the range of 5-15 cm during the actual construction.Based on the comparative analysis of the response surface method,it is found that the factors that most significantly influence the contact stress of the ball hinge,in descending order,are support radius,exposed height,and curvature radius.