基于能量变分法的曲线组合箱梁畸变效应分析

Distortion Effect Analysis of Curved Composite Box Girder Based on Energy Variation Method

目的研究曲线钢与混凝土组合箱梁主要设计参数对畸变效应的影响,减小组合梁的畸变。方法通过能量变分法建立曲线组合箱梁畸变方程,分析集中荷载作用下截面尺寸及曲率半径对曲线组合箱梁畸变效应的影响。结果增加钢腹板厚和梁高可显著减少畸变效应;箱梁的曲率半径不宜过小,当曲率半径小于100 m时畸变效应明显;梯形截面比矩形截面更有利于限制结构畸变,为控制畸变效应,根据曲率半径的差异,主控不同的设计参数。结论当曲率半径小于100 m时,曲线组合梁的高跨比宜为0.6,高宽比宜为1,钢腹板厚宜大于30 mm;当曲率半径大于100 m时,主要通过增加钢腹板厚控制畸变,其厚度宜为20~40 mm。

To reduce the distortion,the influence of main design parameters of the curved steel and concrete composite box girder on the distortion effect was studied.The distortion equation of curvilinear composite box girder was established by using the energy variation method,and the influence of section size and curvature radius on the distortion effect of curved composite box girder under concentrated load was analyzed.The results showed that the distortion was reduced effectively by increasing the thickness of steel plate and the height of beam.The curvature radius of box girder should not be too small.When it was less than 100m,the distortion effect was obvious.Trapezoidal section was more beneficial to limit the structural distortion than rectangular cross section.To control the distortion effect,different design parameters should be focused on,depending on different curvature radiuses.When the curvature radius is less than 100 m,appropriate height-span ratio of curved composite box girder is recommended to be 0.6,the height-width ratio should be 1,and the thickness of steel web should be greater than 30 mm.When the radius of curvature is greater than 100 m,the distortion is mainly controlled by increasing the thickness of steel web,and the recommended thickness is 20~40 mm.