后张预应力混凝土管桩分批张拉预应力损失

后张法预应力混凝土大管桩由于抗弯承载力高和成本低，在港口工程中得到广泛应用。由于大管桩张拉过程中采用多批次张拉，需要精确计算各批钢绞线张拉应力。针对大管桩分批张拉施工技术提出的计算方法可以求解预应力筋的施工控制张拉力，使得每根预应力筋张拉一次即可，无需反复调整张拉力。根据不同张拉顺序的方案，计算出张拉顺序对构件应力和变形的影响，应用于预应力施工方案的优化设计。

Batch Prestress Loss of Concrete Pipe Pile by Post-Tensioning Method

Prestressed concrete pipe piles by post-tensioning method are widely used in harbor engineering because of its high flexural bearing capacity and low cost. As the large diameter pipe piles require multi-batch tensioning, tension stress of steel wires must be accurately calculated. Based on the unique prestress applying method of large diameter pipe piles, this paper de- rives calculation formulas for stress loss of each batch steel bars. All prestressed steel bars can be tensioned to their designed tension value at once, if each bar is tensioned to its construction control tensile force as calculated by this method, according with different tensioning schemes, the influence of the tensioning sequence on stress and deformation is calculated and the tensioning sequence is optimized.