超宽超重T构转体桥梁体应力和线形变化研究

Research on Stress and Linear Change of Super Wide and Overweight T Structure Rotating Bridge Body

在目前复杂的桥梁结构建设中,为了更好地研究超宽超重T构转体桥整体稳定性,除了与设计图纸、施工工艺、现场环境等有密切关系外,更应注重对桥梁施工过程和转体过程进行线形和应力监控。本文采用有限元软件Madis/civil建立主梁结构模型,对桥梁施工全过程进行仿真模拟,分析关键施工阶段的结构受力特点和变形状况以及成桥后的结构受力情况,确保桥梁施工过程安全。同时,现场采用水准仪、应力传感器等对转体前、转体过程中、转体后梁桥的线形和应力进行现场实时测量。最后将设计值、有限元分析值和现场实际值进行比较,并分析其差异。结果表明,仅对梁体而言,支架拆除后,位移变化值从中间向两端逐渐增大,应力变化则与位移变化相反;通过有限元分析,调整位移量使得现场线形变化趋势与设计线形变化趋势大体一致,应力值在合理的设计范围之内。

In the current complex bridge structure construction,in order to better study the overall stability of super-wide and overweight T structure rotating bridge,linear and stress monitoring of bridge construction process and rotation process must be carried out particularly except considering the close relationship with design drawings,construction technology and site environment.In this paper,the main beam structure model was established by using the finite dement software Madis/civil,for the purpose of simulating the whole process of bridge construction,analyzing the structural stress characteristics and deformation of the key construction stages and the structural stress after the completion of the bridge,thus ensuring the safety of bridge construction process.Meanwhile,the level and stress sensor were used to measure the line shape and stress of the bridge before,during and after the rotation.Finally,the design value,the finite element analysis value and the actual value in the field were compared,and the differences were analyzed.The results show that only for beams,the displacement change value increases gradually from the middle to the two ends after the support is dismantled,and the change of stress is opposite to the change of the displacement.Through the finite element analysis,the adjustment of the displacement makes the change trend of the line shape consistent with the change trend of the design line shape,and the stress value is within the reasonable design range.