梁墩刚度分布对连续梁桥横桥向规则性的影响

以4跨连续梁桥为例,研究了梁、墩横向刚度比,桥墩横向刚度分布情况与连续梁桥横桥向规则性的关系.利用推倒分析方法,将全桥结构简化为单自由度体系,比较在不同地震动输入下,分别由全桥模型和等效单自由度体系计算所得最大位移响应的差异,并以此来判断连续梁桥横桥向规则性的好坏.研究表明:梁、墩横向刚度比对连续梁桥横桥向规则性起控制作用,梁、墩横向刚度比越大,梁桥规则性越好;而桥墩刚度分布情况只有在梁、墩横向刚度比较小时,对规则性影响较大.最后,在大量分析基础上,将梁、墩横向刚度比作为规则连续梁桥划分指标,建议了量化的规则连续梁桥划分标准.

Effects of Girder and Pier Stiffness on Continuous Bridge Regularity in Transverse Direction

A series of four-span continuous bridges is investigated to identify the effects of the girder-pier stiffness ratio and stiffness distribution among piers on continuous bridge regularity in transverse direction.Each bridge is equalized as a single-degree-of-freedom model through pushover analysis.The bridge regularity is evaluated based on comparison of maximum displacement responses calculated with a multi-degree-of-freedom model and the corresponding single-degree-of-freedom model respectively under different seismic inputs.Results show that the girder-pier stiffness ratio is the key factor that determines continuous bridge regularity in transverse direction.Bridges with larger girder-pier stiffness ratio are more regular.Pier's stiffness distribution,however,influences regularity only when the girder-pier stiffness ratio is small.Finally,based on the girder-pier stiffness ratio,a quantitative criterion for regular continuous bridges is proposed.