PC箱梁横隔板对其截面应力影响的空间分析

对一座铁路三跨连续PC刚构桥变截面宽幅箱梁进行了空间应力分析.分析结果表明,预应力空间效应、箱梁剪力滞及畸变等因素使箱梁顶、底板应力沿横向分布出现很大起伏,箱梁横、纵向应力沿横向出现明显的不均匀,截面变形也表现出畸变和不平顺性.为了减轻和克服这种不利的受力状态,增设横隔板能显著增大结构的横向刚度,达到减少箱梁顶、底板应力峰值,降低应力不均匀性的效果.本文得出的结论可为同类桥梁的设计和施工提供一定的参考.

Spatial Analysis of Diaphragms of PC Box Girder Effecting on the Section Stress

There is an analysis of spatial stress on variable cross-section wide box girder of three-span continuous PC rigid frame bridge in the paper.The results of the analysis show that the spatial effect of prestressing stress,shear lag of box girder and distortion cause the stress of the top and bottom of box girder to be great fluctuate along transverse,the transverse stress and longitudinal stress to be significant uneven along transverse and the sectional deformation to be deformed and uneven,too.In order to reduce and overcome this negative forced state,the structural analysis indicates that adding cross baffle can increase the transverse stiffness significantly and come to a purpose of reducing the peak value of stress on the top and bottom of box girder,and decreasing stress nonuniformity.The analysis offers reference to the design and construction of similar bridges.