带一字肋组合桥面板横向受力简化计算方法研究

SIMPLIFIED CALCULATION METHOD FOR TRANSVERSAL FORCE OF COMPOSITE BRIDGE DECK WITH SLAB RIBS

为优化正交异形钢桥面板传统解析方法,采用简化平面框架体系模型,理论推导了钢桥面板和纵肋交界处的最大横向弯矩解析表达式,利用随机有限元模型验证了算法的正确性。文中所提出的组合桥横向受力简化计算法能够快速准确实现轮载作用下带一字肋桥面板横向弯矩及应力的计算,研究发现相比有限元结果,使用简化计算的方法所得横向应力略大,更偏保守。从理论层面分析,组合桥面板相对于纯钢桥面板横向应力的降低,原因在于相同荷载作用下,UHTCC层的存在增大了原钢桥面的纵肋底部弹性支撑刚度和顶板横向抗弯刚度,其中在与纵向加劲肋连接处的桥面板拉应力降低幅度最大。

To optimize the traditional analytical method of the orthogonal steel bridge deck,the analytical expres⁃sion of the maximum transversal moment at the junction of the steel bridge deck and the longitudinal ribs was theo⁃retically deduced by using the simplified plane frame system model.And the correctness of the algorithm was veri⁃fied by random finite element model.The transversal moment and stress of the deck with slab ribs under wheel loads can be quickly and accurately calculated by the simplified calculation method for lateral force of composite bridge.Compared to the finite element results,the transversal stress obtained by the proposed method was slightly larger and more conservative.From the theoretical analysis,the existence of the UHTCC layer increases the elastic support stiffness of the longitudinal rib bottom and lateral bending stiffness of the deck under the same load.It leads to the reduction of the transversal stress of the composite bridge deck,in which the tensile stress of deck decreases the most at the connection with the longitudinal stiffeners.