Abstract: "The method of external post-tensioning is widely used in strengthening the large span continuous rigid frame bridges.The strengthening efficiency is reduced for the restraint effects due to the piers and the supports.The beam-cable element is established to analyze the internal force distribution and the displacement of the structure according to the steps of construction.Then the strengthening efficiency is discussed,which is affected by the restraint effects due to the piers and the supports.And it will be the reference to the same kind of bridge in calculation and strengthening design.

Key words: continuous rigid frame bridges, retrofitted by external post-tensioning, the restraint effects, strengthening efficiency

摘要： 大跨径连续刚构桥的加固多采用施加体外索的方式,由于主墩及支座的约束作用,影响了加固效果。建立了梁-索单元组合有限元模型,分析体外预应力施加过程中,结构的内力分布及变形情况;讨论了由于主墩及边支座的约束效应对连续刚构桥主梁加固效果的影响程度,对同类型桥梁的加固设计具有一定的参考作用。

关键词: 连续刚构桥, 体外索加固, 约束效应, 加固效率