大跨度连续刚构桥0#、1#块托架钢绞线反拉预压施工技术

Construction Technology of Steel Strand Backtension Preloading for Long-span Continuous Rigid-frame Bridge 0# and 1# Block Brackets

摘要:

连续刚构桥0#、1#块采用托架法施工较为常见，而0#、1#块是全桥施工的基础段，其主要特征为截面高以及重量大，故在托架安装完成后必须对其进行预压，以验证其安全性，并得到托架的变形数据，从而设置预拱度。结合工程实例，通过介绍连续刚构桥0#、1#块托架钢绞线反拉预压施工技术，着重描述钢绞线和精轧螺纹钢的选定、钢绞线反拉预压系统的安装以及钢绞线张拉加压、持荷和卸载的措施，得到了科学有效的托架变形数据，为该桥预拱度的设置提供了依据，也为今后类似桥梁工程施工提供参考。

Abstract:

It is more common for the 0# and 1# blocks of the continuous rigid-frame bridge to be constructed by the bracket method, and the 0# and 1# blocks are the foundation sections of the whole bridge construction. The main characteristics are high cross-section and large weight, so the bracket must be preloaded after erected in order to verify its safety. And the deformation data of the bracket are obtained so as to set the precamber. Combined with the engineering examples, the construction technology of steel strand backtension preloading for the continuous rigid-frame bridge 0# and 1# block brackets is introduced, and the focus is on the selection of steel strands and finished rolled rebar, the installation of the backtension preloading system of steel strands, and the measures of tension and compression, load holding and unloading of steel strands. The scientific and effective bracket deformation data are obtained, which provides a basis for the setting of the precamber of the bridge and a reference for the construction of similar bridge projects in the future.