预应力雁形板屋盖纵向开裂和挠度分析

Analysis on Longitudinal Cracks and Deflection of the Pre-stressed V-shape Slab Roof Structure

采用有限元法对雁形板屋盖结构的空间受力特性进行了分析计算 ,并着重考虑了温度变化对板截面应力的影响。计算结果表明 ,温度上升在肋梁附近的翼板下部将产生超过混凝土抗拉强度的拉应力 ,导致雁形板沿纵向开裂 ,形成贯通板全长的纵向裂缝。同时 ,建立了裂缝形成后的计算模型进行板的挠度分析计算 ,计算结果和实际变形相一致。

In this paper, the finite element method is used to analyze the behavior of the prestressed V-shape Slab Roof structure, especially the effect of temperature change on the stress of slab. The calculated results indicate that when the temperature changes, the tensile stress at the lower extreme fibers of the flange plate near rib exceeds the tensile strength of concrete subjected to the combined action of triaxial stresses and results in the longitudinal cracks of the flange plate. The deflection analysis is based on the mechanical model of the prestressed V shape slab with the longitudinal cracks. The calculated results are in general agreement with the field observations.