大跨连续梁0号段分层施工支撑结构受力研究

Study on Force of Supporting Structure in Section No. 0 of Large-span Continuous-beam Under Construction in Layers

通过大西铁路19号墩大体积0号梁段分层浇筑施工,在施工现场分别测试现浇第一层、第二层0号段梁体时支架和临时支墩的应变情况,并对结构建模进行理论分析验证。验证结果表明:分层浇筑混凝土时,第一层已浇混凝土与临时支墩可与现浇支架共同形成承力结构;在现浇第二层混凝土时,现浇支架受力增量很少,主要荷载由已浇结构承担。分析结果对工程中同类的支架设计起到指导作用,可供类似工程参考借鉴。

The large-volume beam section No. 0 of pier 19 on Datong-Xi'an Railway was built by pouring in layers,when the 1stand 2ndlayers there of were placed on the construction site,the strain situations of both the support and the temporary pier were tested respectively,and the structural models were analyzed by theory and then verified. The results show that,in case of the concrete placement in steps,the concrete in the first placement and the temporary pier form the bearing structure jointly with the cast-in-place support; and when pouring the second time,the support has little increment in force and the main load was supported by the existing structure. It plays a positive role in guiding design of similar support in the engineering,and can be the reference to similar projects as well.