南广铁路西江特大桥的技术创新

对南广铁路西江特大桥的总体设计方案进行了研究,确定了486 m中承式钢箱提篮拱桥的主要设计参数,并对"边段竖转+中段提升"、"缆索吊机节段悬拼"总体施工方案进行了研究;结合"前临西江后靠陡峭山坡"的基础工程特点提出了可承担巨大水平力的新型基础结构形式、计算分析方法,并对其深基坑支护方案进行了研究;经全桥风洞试验和列车走行性分析,发现加大桥面系质量可同时解决大跨度钢箱拱的风振问题、提高大桥高速列车的行车性能;设计了能适应空间转角变化的新型吊索锚固构造,并进行了试验验证;利用地质力学理论对大桥施工中的软弱围岩区拉索锚碇及边坡稳定性进行了分析,解决了大桥施工的安全性问题,确定了预应力锚索的各项参数。

Technological Innovation of Xijiang Bridge in Nanning-Guangzhou Railway

Xijiang Bridge in Nanning-Guangzhou Railway is a super major bridge.Firstly,its general design scheme was studied,the main design parameters of the 486 meters half-through steel-box basket-handling arch bridge were determined,and the general construction schemes of "vertically rotating the side sections+elevating the middle one","segment cantilevered assembly by cable crane" were researched.Also,considering the features of foundation works of "confronting the river and lying on the steep hillside",a new foundation structure which could bear great horizontal force and a new calculating analysis methods were proposed,and the supporting scheme for deep foundation pit was studied.Then after the whole bridge wind tunnel test and train running analysis,it was found that the wind-induced vibration problem of large span steel-box arch bridge could be solved and the running performance of high speed train on this bridge could be improved simultaneously by increasing the weight of bridge deck system.Furthermore,a new type of hanger anchoring structure which could adapt to spatial angle variation was designed and verified by testing.Finally,by using geological mechanics theory,the slope stability and the anchorage issues of the anchor cable in weak surrounding rock region were analyzed,therefore the construction security problems of this bridge were solved and the parameters of prestressed anchor cable were determined.