随机地震作用下三跨曲线箱梁桥剪力滞效应研究

Shear lag effect research on three-span curved box girder bridge under random seismic action

制作了1:20的三跨连续曲线箱梁有机玻璃缩尺模型进行振动台试验,研究地震作用下主梁各典型截面剪力滞效应,并与ANSYS有限元数值结果相比较,二者基本吻合,在试验验证有限元模型可靠的基础上,采用有限元法分析了非径向支撑对连续曲线箱梁剪力滞的影响。结果表明:在地震作用下,三跨连续曲线箱梁内支座截面剪力滞效应最为显著,中跨跨中截面次之,边跨跨中截面最小;非径向支撑角和支撑方向对剪力滞影响较大,连续曲线箱梁剪力滞效应对支撑角等外部几何参数变化比较敏感。

In order to study typical cross sections’ shear lag effect of primary beam under seismic excitation, a organic glass reduced scale model(1:20) of continuous curved box girder with 3 spans is made, and the vibration table test is conducted. Then compared the experiment with finite element analysis of ANSYS, they basically agree with each other. On the basis of reliable finite element model verified by experiment, the influence of non-radial support on shear lag effect of continuous curved box girder is analyzed by finite element method. The results indicate that for continuous curved box girder, shear lag effect of inner support cross section is most prominent under seismic excitation, the next is mid-span cross section at middle span, and the shear lag effect of mid-span cross section at side span is minimum;non radial support angle and direction have a great influence on shear lag effect, shear lag effect of continuous curved box girder is sensitive to the change of support angle and other external geometrical parameters.