连续梁拱组合桥梁边中跨比影响分析

Analysis on Influence of Side-to-mid-span Ratio of Continuous Beam-Arch Composite Bridge

连续梁拱组合桥梁主梁和拱肋协同受力,整体刚度大、跨越能力强。以三跨连续梁拱组合桥梁为工程背景,分析了边中跨比对桥梁内力、变形、支反力、自振频率、稳定等方面的影响。分析发现:桥梁主梁和拱肋的内力、变形,主梁边支点的支反力随边中跨比的增大而增大,且在恒载作用下边中跨比0.400时边支点出现负反力;桥梁自振频率随边中跨比的增大而减小;桥梁施工阶段稳定系数随边中跨比的增大而减小,成桥状态稳定系数随边中跨比的增大而增大,但稳定系数变化率均较小;连续梁拱组合桥梁的合理边中跨比建议在0.425~0.500之间。

The main beam and arch ribs of a continuous beam-arch composite bridge are synergistically stressed with large overall stiffness and strong spanning capacity.Taking a three-span continuous beam-arch composite bridge as the engineering background,the effect of the side-to-mid-span ratio on the internal force,deformation,support reaction force,natural vibration frequency and stability of the bridge is analyzed.It is found that the internal forces and deformation of the main beam and arch ribs,and the support reaction force at the side supporting point of the main beam increase with the increase of the side-to-mid-span ratio,and the negative reaction force appears at the side supporting point when the side-to-mid-span ratio is 0.400 under the constant load.The natural vibration frequency of the bridge decreases with the increase of the side-to-mid-span ratio.The stability coefficient of the bridge during the construction stage decreases with the increase of the side-to-mid-span ratio.The stability coefficient of the finished bridge state increases with the increase side-to-mid-span ratio,but the rate of change of the stability coefficient is small.The reasonable side-to-mid-span ratio of continuous beam-arch composite bridge is recommended to be between 0.425 and 0.500.