【摘要】 为掌握空腹式连续刚构桥在自重、汽车荷载作用下桥梁关键截面内力分布特征与腹板挖空率和弦梁刚度比的关系,以有限元法为基础,借助结构分析软件建立了空腹式连续刚构桥的数值模型,计算了自重、汽车荷载作用下跨中弯矩、上下弦梁接合处弯矩、弦梁墩顶截面弯矩以及下弦梁弯矩。论文还研究了这些截面弯矩比随着挖空率、弦梁刚度比的变化规律。研究表明腹板挖空率的增加,会缩小空腹段的负弯矩与实腹段的负弯矩的差距,但会放大实腹段內正负弯矩的差距。上下弦梁刚度比变化不影响实腹段弯矩分配,但上下弦梁负弯矩大小按它们刚度比进行分配,刚度比为0.25时,上下弦梁最大负弯矩相近。更多还原

【Abstract】 In order to investigate the internal force distribution in key section,and the relation between web hollow rate and the chord beam stiffness ratio of open-web continuous rigid frame bridge under the action of deadweight and vehicle load,a numerical model of the bridge is built with structure analysis software based on FEM. The bending moments in the mid-span section,in the section of upper and lower chord connection,in the section of upper chord pier top and in the section of lower chord under the action of deadweight and vehicle load are calculated. The rules of these bending moment ratios varying with the hollow rate and the chord beam stiffness ratio are researched. The research shows that( 1) the increase of web hollow rate reduces the difference of negative bending moments between open and solid sections,magnifies the difference of negative and positive bending moments in the solid section;( 2) the change of the stiffness ratio between upper and lower chords has no influence on the bending moment distribution in solid section,but the negative bending moments in upper and lower chord beams are distributed according to the stiffness ratio;( 3) the maximum negative bending moments of upper and lower chord beams become similar when the stiffness ratio between upper and lower chords is 0. 25.更多还原