车载作用下超宽混凝土箱梁自锚式悬索桥静力特性

Static characteristics of self-anchored suspension bridge with super wide concrete box girder under vehicle loads

为了探讨超宽混凝土箱梁自锚式悬索桥在车载作用下的受力状态,通过实桥荷载试验和ANSYS有限元分析,研究了结构整体静力特性以及超宽加劲梁的纵向应力水平及其分布.试验结果表明:在相当于设计汽车荷载水平的试验荷载下,主塔顶横桥向位移较纵桥向明显;受剪力滞效应、横坡及车轮局部效应的影响,超宽加劲梁受力空间效应明显,对称车载作用下加劲梁挠度沿横桥向呈V形变化,最大可达35 mm,偏心车载作用下扭转变形明显;加劲梁顶、底板纵向应力沿横桥向呈不均匀分布,最大纵向应力增量位于顶、底板与内腹板交接处,对称车载作用下顶板纵向应力沿横桥向呈M形变化;偏心车载作用下缆索系统受超宽加劲梁的空间效应影响,两侧索面受力的不均匀性较为明显.

To investigate the mechanic properties of the self-anchored suspension bridge with the super wide concrete girder under the vehicle loads,the global static characteristics as well as the longitudinal stress levels and the transverse distributions of the super wide girder were analyzed by the bridge load test and ANSYS finite element analysis. The results showthat the transverse displacements of the towers are more obvious than the longitudinal displacements under the test load equivalent to the designed vehicle load level. Subjected to the shear lag effect,the cross slope and local effect of the wheels,the spatial effect of the super wide girder is obvious. The deflection of the girder along the transverse direction exhibits V-shaped change under the symmetrical vehicle loads,the maximum of which is 35 mm,and the torsion deformation under the biased vehicle loads is also obvious. The longitudinal stresses of the top and the bottom plates of the girder distribute unevenly along the transverse direction of the girder,and the maximum of the longitudinal stress increments are located in the junctions of the inner web and the top and bottom plates. The longitudinal stress increment of the top plate shows M-shaped change under the symmetrical vehicle loads. The unevenness of the force state between the two cable surfaces is obvious under the biased vehicle loads due to the spatial effect of the super wide girder.