梁墩刚度分布对连续梁桥横桥向规则性的影响

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

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.

A series of four-span continuous bridges is investigated to identify the effects of the girderpier 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 un- der different seismic inputs. Results show that the girder-pier stiffness ratio is the key factor that de- termines 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.