混合梁斜拉桥H型索塔施工关键技术

南沙港铁路西江特大桥跨西江主桥为(2×57.5+172.5+600+4×57.5)m的双塔双索面等高塔混合梁斜拉桥,塔柱采用单箱单室截面的H型索塔设计,主塔塔座以上塔高分别高208 m和200 m,针对索塔线形控制要求高、上下横梁支撑难度大、钢锚梁定位精度要求高等特点,通过采用塔梁异步浇筑的方法,形成了索塔临时对撑技术、下横梁落地式支架现浇技术、上横梁牛腿托架现浇技术及索塔施工线形控制技术,实现了超高索塔的高效施工,并提升了建设质量。

Key Technology for the Construction of H-shaped Pylon of Hybrid Girder Cable-stayed Bridge

The main bridge of Xijiang Bridge on Nansha Port Railway across Xijiang River is a(2×57.5+172.5+600+4×57.5) m hybrid girder cable-stayed bridge with double towers and double cable planes.The H-shaped pylon with a single box and single chamber section is adopted for the design of the tower column,the height of the tower above the main tower is 208 m and 200 m respectively.In the paper,according to the characteristics of high requirements of pylon linear control,difficulties in upper and lower beam support and the high precision of steel anchor beam positioning,the author adopts the method of asynchronous pouring of the tower beam,which forms the pylon temporary bracing technology,cast-inplace technology of console support for the lower beam,cast-in-place technology of corbel bracket for the upper beam and the linear control technology of pylon construction,achieves the efficient construction of ultra-high pylon and improves the quality of construction.