三跨预应力混凝土连续箱梁梁端底板斜向裂缝评估

Evaluation of Oblique Cracks in Bottom End of Three-span Prestressed Concrete Continuous Box Girder

一城市高架桥梁端底板存在斜向裂缝,与常见裂缝形态、裂缝走向和分布位置不同。对这种裂缝产生的原因及处置措施尚无工程案例可供参考。为研究裂缝产生的原因及对桥梁结构整体受力产生的影响,通过对梁端预应力张拉过程进行计算模拟,分析预应力张拉过程中梁端应力变化,并通过荷载试验对结构受力性能进行验证。分析结果表明,梁端底板斜向裂缝由预应力张拉过程中应力变化所致,裂缝对结构整体受力影响较小,为非结构裂缝。

Oblique cracks were found in bottom end of the urban viaduct,which were different from the common crack form,direction and distribution.The causes and treatment measures of the cracks were not available for reference.In order to study the cause of crack and its influence on the force of bridge structure,the prestressing process of the girder was simulated to analysis the variation of stress.The mechanical properties of the structure was verified by loading test.Analysis results showthat the oblique crack caused by the variation of stress in the prestressing process.The crack has little influence on the structure of the structure,which it is not structural crack.