大跨径PC连续梁桥悬臂施工中的工艺控制

Process Control Technology During Cast-in-place Cantilever Construction in Long Span Prestressed Concrete Continuous Beam Bridge

结合实例,分析大跨径预应力混凝土连续梁桥在悬臂施工过程中温度对主梁结构应力和挠度的影响。通过合理选择立模时机和在不同温度下适当调整立模标高,使主梁线形平顺。在梁体温度均匀时张拉预应力钢束,可减少结构的预应力损失。结构应力和应力增量的确定,为改进施工工艺参数提供了科学依据。

This paper analyses the effect of temperature on deflection and structural stress of main beam during cast-in-place cantilever construction in long span prestressed concrete continuous beam bridge with a practical example. An even alignment of main beam is formed by the rational selection of the time for the mould plate location and the adjustment of elevation of the mould plate under different temperature. The prestressed steel bar is drawn when there is uniform temperature of the main beam body, so that the prestress loss can be decreased. The determination of structural stress and its increase quantity is the basis for the improvement of parameters of construction technology.