重庆鹅公岩轨道专用桥为主跨600 m的双塔双索面自锚式悬索桥,全桥采用“先梁后缆”法施工.由于跨中钢箱加劲梁无法采用支架法施工,提出了“先斜拉,后悬索”的总体施工方案.为选择合理的体系转换方案,保证施工安全,对2种方案(方案1:临时斜拉桥成桥后直接进行体系转换;方案2:临时斜拉桥成桥后,先对斜拉索进行补张拉,再进行体系转换)进行比选,通过张拉设备、吊索张拉次数和接长杆的长度等方面综合比选,选择方案2.利用ANSYS软件进行全桥结构体系转换过程数值模拟仿真分析,结果表明,采用方案2施工,加劲梁及主缆的线形有限元分析结果与设计预期目标吻合较好.%The Egongyan Rail Transit Special Use Bridge in Chongqing is a self-anchored suspension bridge with double towers,double cable planes and with the main span of 600 m.The whole bridge of the bridge was constructed in a way of erecting the stiffening steel box girder before installing the main cables and suspenders.Since the girder at the midspan of the main span could not be erected,using the scaffolding method,the construction scheme of staying the girder first and suspending it late was proposed.To select the rational system transfer scheme for construction of the bridge and to ensure the construction safety,2 schemes were compared.For the scheme 1,after the temporary cable-stayed bridge was completed,the system transfer was carried out directly.For the scheme 2,after the temporary cable-stayed bridge was completed,the stay cables of the bridge were supplementally tensioned first and the system transfer was then carried out.Through the further comprehensive comparison of the tensioning equipment,tensioning times of the suspenders and length of the extension members,the scheme 2 was selected and the software ANSYS was used to implement the numerical simulation analysis of the system transfer process of the whole bridge.The results show that with the selected scheme 2,the finite element analysis of the alignment of the erected stiffening steel box girder and the installed main cables are well agreeable with the anticipated target of the design.
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