山区大跨径悬索桥索塔设计与施工方案研究

Design and Construction Scheme of the Cable Tower of Long-span Suspension Bridges in Mountain Areas

主跨1200m的赤水河大桥采用投建一体、EPC+BOT模式建设,桥位处于川黔峡谷。为了降低山区悬索桥索塔现场施工难度和安全风险,加快施工进度,节约工程投资,采用有限元软件建立了全桥和裸塔模型,分析了索塔在恒载、风荷载、温度和汽车等荷载作用下索塔的稳定、塔柱截面强度和横梁截面强度。经过计算分析,优化了索塔构造尺寸和配筋设计、提出了塔梁异步施工和大节段滑模施工方案,提高了施工效率,保障索塔提前封顶,实现了桥梁设计与施工的深度融合。

The project of Chishui River Bridge with 1200m main span,lying in the Sichuan-Guizhou gorge applies a way of deep integrating investigation and construction,namely EPC+BOT mode.To decrease the difficulty of the construction and security risk as well as save the investments and speed up the construction,full bridge and the free-standing tower are built through the finite element software.Specifically,this paper analyzes the stability of the cable tower and the strength of its column section and beam section under varions conditions of dead load,wind load,temperature,and automobile load of the cable tower.The numerical results show an optimization of the size of the cable towel and the design of steel bars.Furthermore,these theoretical analysis suggests and supports a more efficient construction scheme of asynchronous building the Tower-Beam and the large section sliding,which was evident in advancing the capping of the cable tower in the project.