摘要
张靖皋长江大桥南航道桥跨度2 300 m,为世界最大跨径悬索桥,南锚碇采用了支护转结构复合地下连续墙基础,对地下连续墙施工质量提出了更高的要求,且存在超深异型槽段,成槽施工质量控制难度大。以南锚碇地下连续墙基础为依托,开展现场工艺试验,从槽壁稳定性控制、成槽施工工艺以及成槽质量控制3个方面系统研究了超深异型地下连续墙成槽施工关键技术,结果表明:采用水泥土搅拌桩以及加强施工过程中的泥浆管理,可以保证超深异型地下连续墙槽壁稳定性;相比于纯铣工艺,抓铣结合施工工艺有利于泥浆指标控制,可以降低清孔换浆时间,更加节能环保,主体工程施工时可将抓铣结合施工工艺推广至其他形状槽段施工;采用加长型孔口导向架可以防止异型槽段成槽时孔型发生扭转,应用勤测勤纠技术实现了超深地下连续墙高精度成槽,高于工程控制要求(1/800),保证了十字型槽段钢箱的顺利下放;采用更具备科学依据的贯入式沉渣厚度检测仪可以对沉渣厚度进行准确检测,从而控制沉渣厚度,保证地下连续墙承载力。
With the main span of 2300 m,the South Channel Bridge of Zhang-Jing-gao Yangtze River Bridge is the largest suspension bridge in the world.The south anchorage adopts the composite diaphragm wall foundation,which imposes higher requirements for the construction quality of diaphragm wall.Moreover,there are super deep special shaped trenches,so it is difficult to control the quality of diaphragm wall.Based on the diaphragm wall foundation of south anchorage,field technological tests are carried out to systematically study the key trenching construction technology for ultra-deep special-shaped diaphragm wall from the aspects of stability control,construction technology and quality control of trench wall.The results show that:the trench stability of the trench wall of the ultra deep special-shaped diaphragm wall can be ensured by using cement soil mixing piles and strengthening the mud management during the construction process.Compared with double-wheel trench cutter,the combination of grab bucket and double-wheel trench cutter is conducive to the control of mud indicators,which can reduce the time for hole cleaning and mud replacement,and is more energy saving and environment friendly.It should be promoted during the construction of the main project.Using the extended guide frame can prevent torsion during the construction of special-shaped diaphragm wall.High-precision grooving of ultra-deep diaphragm wall is realized by using frequent measurement and correction technology,which is higher than the project control requirements 1/80o and ensures the smooth lowering and installation of steel box.The penetration type sediment thickness detector with more scientific basis is used to accurately detect the sediment thickness,which is used to control the sediment thickness and ensure the bearing capacity of the diaphragm wall.
作者
朱其敏
朱俊涛
夏欢
王通
戴俊平
Zhu Qi-min;Zhu Jun-tao;Xia huan;Wang Tong;Dai Jun-ping(CCCC Second Harbour Engineering Co.Lt.,Wuhan 430040,China;Jiangsu Communications Engineering Construction Bureau,Nanjing 210004,China)
出处
《公路》
北大核心
2023年第6期107-114,共8页
Highway
关键词
张靖皋长江大桥
复合地下连续墙基础
现场工艺试验
超深异型地下连续墙
成槽施工关键技术
Zhang-Jing-gao Yangtze River Bridge
composite diaphragm wall foundation
field technological test
ultra-deep special-shaped diaphragm wall
key trenching construction technology
