惠新大道跨东江大桥16#主墩双壁钢围堰关键施工技术

摘要

The main span of Huixin highway across Dong river bridge is(76+2×128+76)m,which is a large prestressed concrete continuous rigid frame bridge.The main piers of the bridge are 15#pier to 17#pier,and the platforms are below the Dong river bed,which belong to the deep water low pile platform.The double-walled steel cofferdam was used as the water retaining structure for the construction of platform.Taking the construction of 16#main pier double-walled steel cofferdam as an example,the key construction technologies for double-walled steel cofferdam were expounded,such as the f irst section of double-walled steel cofferdam in-situ assembly,extending height under self-floating,laying down the steel cofferdam to the river bed,auxiliary sinking and positioning, underwater concrete bottom sealing and so on.Practice shows that the construction process is simple,safe and reliable.The diff icult construction problems are solved,such as an obstacle to the sinking of steel cofferdam.The technology has a certain reference value for the construction of deep water low pile platform in sand gravel stratum.%惠新大道跨东江大桥主跨跨径(76+2×128+76)m,为大型预应力混凝土连续刚构桥.该桥15#~17#墩为主墩,其承台都在东江河床面以下,属于深水低桩承台.设计采用双壁钢围堰作承台施工挡水结构,以16#主墩双壁钢围堰施工为例,阐述双壁钢围堰首节原位拼装、自浮接高、下放着床、辅助下沉就位、水下混凝土封底等关键施工技术.实践证明采用的施工工艺操作简单、安全可靠,解决了下沉遇阻等施工难题,对砂卵石地层中深水低桩承台的施工具有借鉴价值.