调顺跨海特大桥钢箱组合梁架设方案比选

Comparison and Selection of Erection Schemes for Superstructure of Combined Steel Box Girders and Concrete Slabs of Tiaoshun Sea-Crossing Bridge

调顺跨海特大桥主桥为(147.5+296+147.5)m双塔双索面全封闭钢箱组合梁斜拉桥。为缩短钢箱组合梁架设工期,提出双节段循环安装架设方案,并与传统单节段循环安装架设方案进行比选。采用MIDAS Civil建立主桥空间有限元计算模型,对2种方案施工阶段钢箱组合梁应力、斜拉索应力,以及成桥状态钢箱组合梁应力、线形及斜拉索索力、应力等各项控制指标进行计算分析。结果表明:2种方案施工阶段、成桥状态各项控制指标计算结果均满足设计及相关规范要求,双节段循环安装较单节段循环安装对施工阶段钢箱组合梁应力影响较大,对施工阶段斜拉索应力及成桥状态各项控制指标影响较小。综合考虑确定采用双节段循环安装架设方案。采用双节段循环安装架设方案成桥状态良好,并节省工期45 d。

The main bridge of Tiaoshun Sea-crossing Bridge is a two-pylon cable-stayed bridge with a main span of 296 m and two side spans of 147.5 m.The superstructure consists of closed steel box girders and concrete slabs that act compositely,and stay cables are fanned out in double cable planes.A two-segment erection cycle was proposed to shorten the construction time.The spatial finite element model of the main bridge was established using MIDAS Civil software.The effectiveness of two-segment erection cycle was compared with the conventional single-segment erection cycle from a series of control indexes,including the stresses in the composite girder,stresses in stay cables during construction as well as the stresses and geometries of the composite girder,and stay cable forces and stresses of stay cables in the completed bridge state.The results show that all these control indexes of either the two-segment erection cycle or the single-segment erection cycle could meet the design and related code requirements during the construction process and in the completed bridge state.During the construction process,compared with single-segment erection cycle,the two-segment erection cycle has greater influence on the stresses in the composite girder,but smaller influence on the stresses in stay cables during construction as well as all the control indexes in the completed bridge state.By comprehensive consideration,the two-segment erection cycle was determined.Tiaoshun Sea-crossing Bridge has been in good condition after the completion of the construction,and the construction schedule saved 45 d.