摘要
深水高墩大部分嵌入河床基岩内的承台采用双壁钢围堰施工时,一般采用围堰内侧封底,需凿除的河床量大,封底混凝土使用量也大,工期也长。为此,结合柳江双线特大桥工程,创新研究了深水高墩承台双壁钢围堰外侧封底技术(获发明专利),即利用钢结构作业平台钻孔成桩机械凿除河床至承台底标高,双壁钢围堰外侧按一定间距布设深入钢围堰底部的双孔压浆管,围堰外侧底部用角钢连接高度1 m的铁板形成封底槽,浇筑外封底混凝土后进行压浆补漏。实践表明:采用双壁钢围堰外侧封底技术,封底密贴,效果良好;减少了河床凿除量及混凝土使用量,缩短了工期,可供类似工程参考。
Double-wall steel cofferdams are usually used for high pier bearing platforms located in deep water with predominantly embedded in riverbed bedrock.In traditional construction methods,it is common to use inner-side bottom sealing for cofferdams,which implies a large amount of riverbed excavation,along with a substantial usage of botom-sealing concrete and an extended construction period.Based on these reasons and combined with the practical problems of the Liujiang Dual-line Extra-large Bridge project,a technology for outer-side bottom sealing of double-wall steel cofferdams for deep water high-pier bearing platforms has been proposed(patent granted).The method utilizes a steel structure working platform with a pile drilling machine to excavate the riverbed down to the foundation level of the pier.Afterwards,on the outer side of the double-wall steel cofferdam,double-hole grouting pipes are arranged at certain spacing,penetrating deep into the botom of the steel cofferdam.At the same time,angle steel is used to connect iron plates with a height of 1 meter on the outer side of the cofferdam bottom,forming a bottom-sealing groove.Finally,pouring of the outer sealing concrete and grouting to fill the leaks.Based on practical experience,it is shown that new method has the advantage of achieving a closely adhered and effective bottom-sealing.It is also pointed out that the new method,compared to traditional approaches,reduces the amount of riverbed excavation and concrete usage,and shortens the construction period.Therefore,it can be used as a reference for similar projects.
作者
李凌峰
LI Lingfeng(China Railway 25th Bureau Group No.4 Engineering Co.Ltd.,Liuzhou Guangxi 545007,China)
出处
《铁道建筑技术》
2024年第3期96-99,165,共5页
Railway Construction Technology
基金
中铁二十五局集团有限公司科技开发计划项目(2023-B-027)。
关键词
双壁钢围堰
外侧封底
双孔压浆
深水高墩
承台
double-wall steel cofferdam
outer-side bottom sealing
double hole grouting
deep water high-pier
bearing platform
