公路工程

对于预应力混凝土斜拉桥,因拉索功能过早衰退而引发的换索问题已经引起了人们的密切关注。为促进拉索的检测、评定及相关养护技术的研究与发展,在全面总结已建桥梁的拉索的构造形式、防腐体系及主要病害的形成机制基础上,对当前的拉索检测与评定技术现状进行了分析与评价。换索通常被认为是延长在役PC斜拉桥使用寿命的最重要的养护技术。根据换索桥梁的技术资料,阐述了换索技术的发展情况及发展趋势,指出新桥的设计应当对运营期换索问题予以充分的考虑,同时应着力开发不中断交通条件下的换索技术,这些均对今后加强拉索检测与评定及换索技术等方面的研究具有重要的借鉴和参考意义。

For existing prestressed concrete cable-stayed bridges,cable replacement due to premature aging functionally of stay cables has caused more and more attention. To promote the study and development on detection,assessment and maintenance techniques of stay cables,configuration forms,external protection systems and key disease mechanisms of stay cables were comprehensively summarized,and then the current status of detection and assessment for cables were analyzed and evaluated. Cable replacement was usually considered as the most effective measure extending the service life of PC cablestayed bridges. Based on technical documentations on cable replacement bridges,the situation and development trend of cable replacement were described. It could be pointed out that the possibility of cable replacement in the running period should be considered at the stage of the origin design of these prestressed concrete cable-stayed bridges. At the same time,cable replacement without interrupting traffic should develop sooner or later. These have important reference for the future to study the detection of stay cables and cable replacement.