深水基础钢套箱钻孔桩施工

三明大桥深水基础在不通航水域，裸露基岩的特殊地质条件下，将圆型钢套箱在预制厂分片分单元利用胎具加工，用浮吊在浮船上作平台，安装胎具进行拼装，用浮船上的龙门吊吊起钢套箱下沉就位于已整平的河床上，安装钢护筒及其导向架，然后灌注封底混凝土，利用钢套箱和钢护筒做钻机施工平台，并设置循环池，进行钻孔桩施工。

Drilling pile construction of depth foundation steel box

Under the special geology condition of innavigable waters and exposed basement, a circular steel box of depth foundation of Sanming large bridge is fabricated in pieces and units by using mould in a precasting plant. The platform is made on the pontoon with floating crane, the mould is installed. The steel box is slung with portal jib crane on the pontoon, it sinks and takes its place on already equating bed. Steel protection tube and rider are installed, and back cover concrete is placed. A constructional platform of rig is made by using steel box and steel protection tube, and a circulating pool is distributed, and drilling piles are constructed.