矮塔斜拉桥0#块应力与剪力滞效应分析

Analysis on Stress and Shearing Force Lag Effect of Block 0# of Short-pylon Cable-stayed Bridge

为了探究矮塔斜拉桥施工时0#块的应力状态和剪力滞效应,以1座跨径组合为(85+160+85)m的矮塔斜拉桥为例,用有限元分析软件Midas FEA NX建立0#块实体单元模型,并以在Midas/Civil全桥模型提取的最大悬臂状态内力作为0#块实体单元模型的边界条件,对0#块进行应力状态和剪力滞效应的分析.结果表明,在该桥最大悬臂状态下,0#块应力状态良好,以全截面受压为主;顶、底板以正剪力滞效应为主,顶板剪力滞变化复杂但数值较小,满足设计规范要求.分析结果可为同类桥型设计和施工提供参考.

In order to investigate the stress state and shearing force lag effect of Block 0# during the construction of a short-pylon cable-stayed bridge, a short-pylon cable-stayed bridge with a span combination of(85+160+85) m is used as an example. Block 0# solid element model is established by the finite element analysis software Midas FEA NX. The maximum cantilever state internal force extracted by the whole bridge model of Midas/Civil is considered as the boundary condition of solid element model to analyze the stress state and shearing force lag effect of Block 0#. The result shows that the stress state of Block 0# of the bridge in the maximum cantilever state is good. Mainly by the total cross-sectional compression, the positive shearing force lag effect is dominant at the top and bottom plates. The shearing force lag variation of top plate is complex, but the numerical value is small, which meets the requirements of design specifications. The analysis results can provide the reference for the design and construction of the similar bridges.