结构参数对梁拱协作机理的影响

Influence of Structural Parameters on the Beam-arch Cooperation Mechanism

以西宁祥瑞街大桥为工程背景,该桥为单拱肋下承式连续梁拱组合桥,以力学分析和有限元建模为主线,围绕梁拱协作机理和结构参数两方面进行研究。根据拱肋分担荷载比、拱梁弯矩比、拱梁变形比的表达式,结合工程背景,绘制各参数(吊杆拱肋等代弯矩刚度比、梁拱截面抗弯刚度比、矢跨比、轴向变形放大系数、边中跨比、边中跨抗弯刚度比)与拱肋分担荷载比、拱梁弯矩比、拱梁变形比的影响曲线,分析各参数对拱肋分担荷载比、拱梁弯矩比、拱梁变形比的影响。为设计人员在方案设计初期,拟定较为合理的结构参数提供了力学依据。

Taking Xiangrui Street Bridge in Xining as the engineering background,it is a single-arch through continuous beam-arch combination bridge,combining with mechanical analysis and finite element modeling as the main line.The following researches were carried out on the beamarch cooperation mechanism and structural parameters.According to the expressions of load sharing ratio of arch,bending moment ratio of arch-beam,and deformation ratio of arch-beam,combined with engineering background,the author draws the influence curves of each parameter(suspender-arch ratio of equivalent flexural rigidity,ratio of beam-arch sectional flexural rigidity,rise-span ratio,influence coefficient of axial deformation,side-to main-span ratio,side-to main-span flexural rigidity ratio)and load sharing ratio of arch,bending moment ratio of arch-beam,deformation ratio of arch-beam were drawn.The influence of structural parameters on the load sharing ratio of arch,bending moment ratio of arch-beam,and deformation ratio of arch-beam was also analyzed.It provides a mechanical basis for designers to formulate reasonable structural parameters in the initial stage of scheme design.