超宽超重曲线高架桥转体施工关键力学性能分析

Analysis of Key Mechanical Properties of Rotating Construction of Ultra-Wide and Overweight Curved Viaduct

以西北地区某桥面单幅宽36.5 m、重近20000 t曲线T构梁转体施工为研究对象,通过建立有限元模型,分析在大温差条件下桥梁上部结构变形情况、承台受力情况、承台温度效应,并对施工安全风险进行合理评估。研究表明:上、下球铰圆形接触面端部较大的水平压力会导致球铰部分区域出现主拉应力,设计时需增大球铰半径或降低球铰高度以减小或消除拉应力;转动球铰对悬臂梁变形有较大影响,将不平衡重量控制在0.8%以内时,可较好降低转动球铰对悬臂梁变形的影响;温度应力引起的承台最大拉应力值满足规范限值要求。

Taking the rotating construction of a curved T-frame beam with a single width of 36.5 meters and weight of 20000 tons in Northwest China as the research object,a finite element model was established to study the deformation of the bridge superstructure,the load on the cap and the temperature effect of the cap under the condition of large temperature difference,and to conduct a reasonable assessment of the construction safety risk.The results show that the large horizontal pressure at the end of the circular contact surface of the upper and lower ball hinge will lead to the main tensile stress in some areas,and the tensile stress can be reduced or eliminated by increasing the radius of the ball joints or decreasing the height of the ball joints.The rotating ball hinge has a great influence on the deformation of the cantilever beam.When the unbalance weight is controlled within 0.8%,the influence can be better reduced.The maximum tensile stress caused by the temperature stress of the cap meets the needs of the code limit.