昆明新机场航站楼无黏结预应力结构设计与张拉

Design and Tensioning of Unbonded Prestress Structure in Kunming New Airport Terminal

昆明新机场航站楼部分梁采用双向无黏结预应力技术。通过精确的温度应力计算,指出无黏结预应力梁配筋原则,以及主梁、次梁、楼板的预应力配筋方案。施工中重点控制预应力筋张拉顺序,即先张拉楼板预应力筋,后张拉楼面梁预应力筋,由中间向外基本保持对称张拉的顺序,最大程度避免预应力损失。张拉过程中通过张拉力和伸长值的双指标控制,有效控制了超长混凝土结构的裂缝。重点介绍了张拉伸长值的计算及测量。

Bidirectional unbonded prestress technology is used in part of beams of Kunming New Airport terminal engineering.By accurate temperature stresses calculation,the reinforcement principle for unbonded prestressed beam is pointed out,the same as reinforcement scheme of main beam,secondary beam and floor.It is indicated that the tensioning sequence for prestressed reinforcement should be controlled mainly during construction,which is tensioning floor reinforcement firstly and beam reinforcement secondly,and from middle to outer with symmetric tensioning to avoid prestress loss to maximum extent.During tensioning,tensioning force and elongation value are controlled to prohibit the cracks of super-long concrete structure.The calculation and measurement for tensioning elongation value are introduced in detail.