斜交角对斜交箱梁桥横梁内力的影响分析

Analysis on Inner Forces of Transverse Beams of Skew Box Girder Bridge Affected by Skew Angle

介绍了梁格法的理论以及纵梁和虚拟横梁截面刚度的计算,建立了空间斜交横梁的刚度矩阵方程。利用梁格法求解恒载和移动荷载作用下不同斜交角度下横梁的内力,并与正交桥横梁内力进行对比,分析了斜交角对横梁内力的影响。结果表明,对于斜交桥边横梁,斜交角度对其弯矩值和剪力值的影响比较显著,且横梁左右两侧内力值存在较大差异,在设计中可以采用非对称形式布置横梁预应力钢束和抗剪钢筋。对于斜交桥的中横梁,斜交角度对其弯矩值和剪力值的影响不明显,横梁左右两侧内力值差异较小。在设计中可按同等条件下正交桥中横梁的布筋对称布置预应力钢束和抗剪钢筋。

The theory of grillage method and the method of calculating section rigidity of longitudinal beam and virtual transverse beam was introduced,and the stiffness matrix equation of skew transverse beam was constituted.The inner forces of transverse beams with different skew angles under dead load and moving load were calculated with grillage method,the inner forces were contrasted with those of transverse beams of right bridge to analyse the inner forces of transverse beams of skew box girder bridges affected by skew angle.The results show that（1） For side transverse beam of skew box girder bridge,skew angle has significant influence on bending moment and shear force,and inner forces of transverse beams have relatively remarkable difference between right side and left side.It is suggested to adopt dissymmetric form to arrange pre-stressing tendons and shear rebars of transverse beams while designing.（2） For middle transverse beam of skew box girder bridge,skew angle has inconspicuous influence on bending moment and shear force,and inner forces of transverse beams have little difference between right side and left side.It is suggested to adopt symmetric form to arrange pre-stressing tendons and shear rebars of transverse beams referring to the arrangement of transverse beams of right bridge under the same conditions while designing.