正循环钻进反循环清孔工艺在钻孔灌注桩穿越超厚砂层施工中的应用

Application of Normal Circulation Drilling and Reverse Circulation Hole Cleaning Technology in Construction of Bored Pile Passing Through Super Thick Sand Layer

武汉东四环线钻孔灌注桩需穿越超厚砂层施工,针对本工程地质条件特点,通过对成孔工艺、清孔工艺进行比选组合和试桩试验,最终确定采用正循环回旋钻机钻进,终孔后采用空压机反循环清孔的工艺,保证了钻孔灌注桩施工的质量和进度。同时,针对性提出了该工艺的关键控制技术,积累了穿越超厚砂层钻孔灌注桩施工的经验。

The bored pile of Wuhan East Fourth Ring Road needs to pass through the super thick sand layer for construction.According to the characteristics of geological conditions of the project,through the comparison and combination of hole forming technology and hole cleaning technology and pile test,it is finally determined that the normal circulation rotary drilling machine is used for drilling,and the air compressor reverse circulation hole cleaning technology is used after the final hole,so as to ensure the quality and progress of bored pile construction.At the same time,the key control technology of the process is put forward,and the construction experience of bored pile through super thick sand layer is accumulated.