清水浦大桥主要施工技术

Principal Construction Techniques of Qingshuipu Bridge

清水浦大桥为主跨468m的连体桥塔分幅组合梁斜拉桥。为保证桥塔桩基施工质量,根据不同深度和地层,采用不同成孔工艺,对钻杆特性、减压钻进、沉渣厚度等进行控制,使其桩基倾斜度小于1/200、沉渣厚度不大于15cm。为保证防洪大堤及基坑安全,采用刚度控制设计方法,在钢管桩外设水泥土搅拌桩止水,并采用控制拔桩速度、回填砂等措施,确保基坑顺利度过洪期。边跨梁段采用桥式起重机安装,桥塔区梁段采用桥式起重机提升,顺桥向滑移就位;中跨梁段采用悬拼吊机安装;在温度变化≤5℃时进行合龙。

The Qingshuipu Bridge is a cable-stayed bridge with jointed pylons and separated composite girders and with a main span 468 m. To ensure the construction quality of the pile foundations of the pylons, the different boring construction technologies were employed in the light of the different stratum depth and conditions and the boring stem characteristics, pressure- reducing boring and slag sediment thickness were well controlled to keep the inclination ratios of the piles less than 1/200 and the slag sediment not thicker than 15 cm. Also to ensure the safety of the flood dyke and foundation pits, the rigidity control method was applied in the design, the cement piles were set outside the steel pipe piles to stop water from coming in and the measures of controlling the speed of extracting piles and backfilling sand were taken to help the construction of the foundation pits to safely tide over the flood period. For construction of the superstructure of the bridge, the girder segments of the side spans were erected by the bridge cranes and the seg- ments close to the pylons were firstly lifted by the bridge cranes and then slid in place in the lon- gitudinal direction of the bridge. The segments of the central span were cantileveredly erected by the deck cranes and the girder of the central span was closed in the time of temperature variation ≤5℃.