狭小空间现浇梁端预应力施工控制技术

Introduction of Narrow Space Cast-in-situ Beam Prestressed Construction Control Technology

后张法预应力施工工艺简洁易行,在桥梁施工中广泛使用,但其施工工艺操作需要足够的空间。以现浇简支箱梁预应力张拉为背景,介绍了狭小空间后张法预应力张拉工艺技术。通过在简支箱梁梁端设置张拉槽,梁端张拉采用挤压锚的方法,相对加大了作业空间,为千斤顶的操作提供了条件。通过提前安装张拉槽模板、端头模、钢绞线选择尺寸较小的穿心式张拉千斤顶等措施,解决了狭小空间预应力张拉的问题,提高了施工进度,节省了工程成本,提高了经济效益,对同类型张设技术提供了有效的借鉴作用。

It is easy to operate the post-tensioned prestressing construction technology,which is now widely used in bridge construction. However,the implementation of this technology requires sufficient space. Based on prestressed tension of the cast-in-situ simply supported box girder,introduces the technology of post-tensioning prestressing in narrow space. By setting a tension groove at the end of the simply supported box girder,the end of the beam is tensioned and the anchor is squeezed,which relatively increases the working space and provides conditions for the operation of the jack. Aiming to solve the problem of narrow space that prestressed tension requires,the stretch groove template,end mould,tensioning centre hole jack of undersized steel strand,etc.,will be installed in advance. Moreover,the progress of the construction is being accelerated,the cost is saved and the economic efficiency is improved,as well. This trial also provides an effective reference for the same type of stretching technology.