高墩双线变四线道岔连续梁施工技术

High Pier Double Track to Four Track Switch Continuous Beam Construction Technology

金华至温州铁路扩能改造工程祯埠特大桥18#～22#墩之间设计1联4×32m双线变四线道岔连续梁，梁面宽度由12．6m渐变至20．72m，箱内结构由单箱双室渐变为单箱三室。设计采用支架法施工，混凝土一次性浇筑、全梁张拉。通过对设计施工方案的优化，采用分段浇筑混凝土、全梁张拉的施工工艺，解决了高墩变截面荷载支架设计、预应力管道穿束、压浆密实度等难题，可为今后类似工程提供参考和借鉴。

Pier beams between 18 - 22# of Zhenbu bridge in Jinhua to Wenzhou expansion project of railway are designed to be 14×32 m double line to four line turnout continuous beam with a width increases from 12.6 m to 20.72 m and the gradient box structure consists of a single box with double chamber to single box three rooms. In the design, the supporting construction is adopted with one-time concrete pouring and all beam tension. In this paper, through the optimization of the design of construction scheme, the construction process of the concrete laid in section and beam tension is used to address the difficulties of the high pier of cross-section load support design, prestressed pipe threading, grouting compactness etc, which can provide reference for similar projects in the future.