摘要
八渡三号大桥主桥位于库区,两岸河床陡峭,跨中地势较为平坦,桩基施工期间水位变化达16 m。为解决在裸岩地质插打钢护筒及其精准定位、施工期间水位大幅变化的难题,采用了“浮式平台+钢护筒+装配式钻孔平台”相结合的平台施工系统进行桩基施工。施工过程中,浮式平台利用抛锚及卷扬机精准定位,利用冲砸机械配合全站仪形成定位坑;采用气举反循环法清孔并沉放钢护筒,浇筑水下混凝土对其进行包裹固定;安装抱箍牛腿及整体式平台,初次形成钻孔平台;利用4点起吊方式进行钻孔平台提升,可形成新的钻孔平台。该钻孔平台设计及施工工艺很好地适应了库区水位变化及裸岩地质施工,为同类桩基施工提供了参考。
The main bridge of Badu No. 3 Bridge is located in the reservoir area, with steep riverbeds on both banks and relatively flat terrain in the middle of the span. The water level changes up to 16 m during the pile foundation construction. In order to solve the problems of inserting steel casing in bare rock geology and its precise positioning, and drastic changes in water level during construction, a platform construction system combining "floating platform + steel casing + assembled boring platform" was adopted for pile foundation construction. During the construction process, the floating platform used anchor and hoist to accurately locate, and used punching machinery to cooperate with the total station to form a positioning pit;air-lift reverse circulation method was used to clear the holes and deposit the steel casing, and poured underwater concrete to wrap and fix it;installed hoop bracket and integral platform to form a boring platform for the first time;used 4-point hoisting method to lift the boring platform to form a new boring platform. The design and construction technology of the drilling platform well adapt to the changes of the water level in the reservoir area and the construction of the bare rock geology, providing a reference for the construction of similar pile foundations.
作者
徐安祺
付甦
黄凤达
XU An-qi;FU Su;HUANG Feng-da(CCCC Second Harbor Engineering Co.,Ltd.,Wuhan,Hubei 430040,China;Key Laboratory of Large-span Bridge Construction Technology,Wuhan,Hubei 430040,China;Research and Development Center of Transport Industry of Intelligent Manufacturing Technologies of Transport Infrastructure,Wuhan,Hubei 430040,China)
出处
《中国港湾建设》
2022年第8期60-64,共5页
China Harbour Engineering
关键词
钻孔灌注桩
钻孔平台
钢护筒
裸岩地质
库区
bored pile
boring platform
steel casing
bare rock geology
reservoir area
