关于后张法预应力施工技术应用探讨
摘要：随着预应力的发展,后张法预应力体系已经广泛应用于大型桥梁结构上,而桥梁工程中预应力混凝土梁板施工存在的问题已经不是一日形成的。本文是作者结合多年工作经验，结合工程实例，对某道路延伸段桥梁工程预应力混凝土连续箱梁采用后张法的施工工艺进行了阐述，施工时严格控制箱梁混凝土浇注、预应力张拉和孔道压浆等施工质量，取得了较好的施工效果。仅供参考。
关键词：后张法预应力；施工; 技术
Abstract: with the development of the prestressed, this method has been used widely in prestressed system of large-scale bridge structures, and bridge engineering, prestressed concrete beam slab construction problems have not formed a day. This paper is based on years of work experience, combined with the engineering practice of a road extension of prestressed concrete continuous box girder bridge engineering, the method of construction technology of this are illustrated, strictly control the construction of prestressed concrete box girder casting, tension and pressure mud and duct construction quality, and have achieved good construction effect. Only for reference.
Key words: this method prestressed; The construction; technology
1.工程概况
某路延伸段桥梁工程共有三座桥，均为预应力连续梁桥。一号桥跨径为28+35×2+28m，为等高度预应力混凝土连续梁桥；二号桥跨径为32.44+45×4+32.44m;三号桥跨径为45+58+45m，均为变高度预应力混凝土连续梁桥。全桥使用1860级φJ15.24钢绞线352吨，798个张拉点数，采用YM15―1型、YM15―12型、YM15―7型、YM15―14型、YM115―9型锚具。其中YJ―14联接器共计80个。预应力连续箱梁混凝土均为C50，桥面宽21m，底板宽16m，悬臂2.5m，设置3%桥面纵坡，采用支座垫石调整坡度。本工程的预应力混凝土连续箱梁都采用后张法的施工工艺。
2.施工特点
在高架桥基础、承台、墩柱与盖梁施工并达到一定龄期后，进行预应力砼连续箱梁的施工。连续箱梁采取分段施工，每节段采用两次浇注，先浇注箱梁的底板、腹板砼，然后立顶模浇注顶板砼。
工艺流程：施上工艺流程:支架基础施工→支架搭设→底腹模板安装→底腹