大悬臂预制盖梁分节安装关键技术

Key Technologies for Segmented Installation of Large Cantilever Prefabricated Cap Beams

S3公路3标段主线高架采用预制装配式工艺,综合考虑构件运输及现场吊装能力,将标准段盖梁分为2节,中间预留2 m湿接段,分节安装后浇筑成整体。分节后大悬臂盖梁安装时重心不在立柱正上方。由于分段盖梁安装后存在偏心,需要采取有效、稳定的临时措施来抵抗盖梁长悬臂下沉带来的安全、质量风险。本工程对分节盖梁安装的2种常用措施:支架法和反拉法进行了实践,对两种工艺的施工难度、受力特点进行了分析,两种方法各有其优缺点,在不同场景下能分别发挥出其特色优势。

Prefabricated assembly process is adopted in the construction of main overhead section of S3 Highway project(Bid section-3).By taking into account the components transportation and on-site lifting capacity,the standard section of capping beam is divided into 2 segments,with 2m long wet joint reserved in the middle,overall pouring process shall be done after respective installation,The center of gravity is not directly above the column during the installation of segmented capping beam with large cantilever.The eccentricity of the segmented capping beam requires the use of temporary measures which can effectively reduce the risks in safety and quality resulting from the sinking of long cantilever of capping beam.In addition,two conventional measures,namely,support method and anti-pull method are put into practice,analyzed from the aspects of construction difficulty and stress characteristics.The results show that the above two adapt to different situations based on the respective advantages and disadvantages.