摘要
长江深泓区一般由长期冲刷形成,水深流急,覆盖层较薄,在此区域建造高桩承台基础的桥梁较为少见,桩基钢护筒往往需要嵌岩,悬臂大,施工难度大,其沉放效果及定位精度关乎钻孔桩的施工质量。以芜湖长江公路二桥南主墩(Z4墩)桩基施工为工程背景,研究深水、浅覆盖层大悬臂嵌岩钢护筒施工技术,对钢护筒沉放关键技术问题进行分析。工程实施效果表明,钢护筒采用分节分批次、钻机扫孔、二次接高跟进的沉放工艺是合理的,钢护筒沉放完成后倾斜度均小于1/260,顶口平面偏位不超过5cm,满足相应规范要求。
The thalweg area of Yangtze River is generally formed by the long-term erosion with great water depth and velocity of flow and shallow overlay where building bridges with high piles and cap foundation is relatively rare. In the region, pile steel casings are needed to be embedded into rock with large cantilever and high construction difficulties, and the sinking effect and positioning accuracy determine the pile construction quality. Pile construction of the south main pier （Z4 pier） of Wuhu Yangtze River Second Highway Bridge as the background, construction technology of large cantilever and rock-embedded steel casings in the thalweg region with shallow overlay is studied, and the key technical problems on steel casing construction are analyzed. Construction effect shows that it is reasonable that steel casings are divided into sections and batches are constructed by firstly drilling part of the holes, then splicing and sinking one more time. After construction, the inclination and top plane deviation of steel casings are less than 1/260 and 5cm respectively, which meet the requirement of relevant standards.
出处
《公路》
北大核心
2015年第12期94-98,共5页
Highway
关键词
长江深泓区
浅覆盖层
大悬臂
嵌岩钢护筒
二次跟进
沉放
thalweg region of Yangtze River
shallow overlay
large cantilever
rock-embedded steel casings
twice splicing and sinking
