钢箱梁正交异性桥面板球扁钢纵肋球头朝向和横隔板空孔的优化

Optimization of Bulb Direction and Diaphragm Cutout of Bulb Flat Ribs in Steel Orthotropic Deck of Box Girder

某钢箱梁正交异性桥面板行车道范围内采用球扁钢纵肋,在横隔板对应部位设置空孔让纵肋连续通过,为研究横隔板的空孔圆弧、空孔与纵肋连接端部等两个细节部位的受力特性,以某立交桥F匝道为工程背景,建立全桥有限元模型,对称荷载作用,对比横隔板对称位置空孔应力分布,分析纵肋球头朝向和背对邻近腹板两种布置对空孔受力的影响。荷载位于不同横向位置,分析横隔板空孔面内受力。荷载位于不同纵向位置,分析横隔板空孔面外受力。对横隔板空孔圆弧半径进行参数分析。研究表明,球扁钢纵肋球头背对邻近腹板和适当增大空孔圆弧半径等措施,可明显改善横隔板空孔圆弧部位受力,但对空孔与纵肋连接端部效果不够明显,需采取进一步措施以改善该细节部位的受力性能。

Bulb flat ribs were used in the range of driveways on the steel orthotropic deck of a box girder,and cutout was set on the diaphragm to let the longitudinal ribs to pass through continuously.In order to probe into the stress characteristics of two details of diaphragm cutout,such as arc of cutout and its joint to rib,finite element analysis was carried out based on the ramp F of an overpass.With the symmetrical vehicle load action,stress distributions of symmetrical cutouts were compared,and the influences of bulb towards and/or back against the adjacent web plate on the stress characteristics of the cutout were studied respectively.For different transverse positions of vehicle load,the in-plane stress characteristics of diaphragm cutout were studied.For different longitudinal positions of vehicle load,the out-of-plane stress characteristics of diaphragm cutout were studied.Then,the parameter optimization of arc radius of cutout was carried out.The results show that the stress along the arc of the diaphragm cutout will be more appropriate when the bulb of longitudinal ribs is back against the adjacent web plate and the arc radius of cutout is increased properly,but for the optimization of stress on the joint of cutout to rib,the above-mentioned measures seem not so effective,and further works are needed to improve the performance of this detail.