满堂支架法直腹板现浇箱梁横向抗推研究

Study on Lateral Thrust Resistance of Cast-in-place Box Girder of Straight Web by Full Framing Method

摘要:

满堂支架法作为一种成熟的施工技术手段，目前被大量应用于城市桥梁现浇主梁的施工项目中。具有施工方便、周转时间短和辅助设备少的优点。但对于直腹板现浇箱梁，尤其是主梁较窄的现浇箱梁，由于混凝土侧压力、倾倒混凝土产生的水平荷载以及振捣产生的水平荷载存在，使得腹板处支架存在较大的水平推力，导致整个结构处于危险状态。以某工程项目为依托，提出了两种解决方案，通过调整斜撑布置形式对结构受力状态进行改善。结果表明，两种方案均可有效降低水平推力作用下造成结构局部应力集中的现象，有利于不利荷载均匀向整个支架结构传递。

Abstract:

As a mature construction technology, the full framing method is widely used in the construction of cast-in-place girders of urban bridges. It has the advantages of convenient construction, short turnover time and less auxiliary equipment. But for the cast-in-place box girder with straight web, especially the cast-in-place box girder with narrow main girder, the existence of the lateral pressure of concrete, the horizontal load produced by dumping concrete and the horizontal load produced by vibration makes the support at the web have a large horizontal thrust to put the whole structure in a dangerous state. Based on a project, two solutions are put forward to improve the stress state of the structure by adjusting the inclined brace arrangement. The results show that both schemes can effectively reduce the phenomenon of local stress concentration of structure caused by horizontal thrust, which is beneficial to the uniform transfer of unfavorable load to the whole framing structure.