复杂地质超长桩基全套筒全回转快速施工技术

Rapid Construction Technology for Ultra Long Pile Foundation with Full Sleeve and Full Rotation in Complex Geological Conditions

结合柳州某轻轨项目超长桩基施工,介绍了全套筒全回转钻机在岩溶极其发育且易发生塌陷的复杂地质地区,通过搭建双工字钢束平台稳定全回转钻机,驱动底部焊有合金刀头的钢套筒使其全程跟进而形成护壁,配合旋挖机在其孔内快速取土成孔,并采用钢筋笼外套钢丝网或永久钢护筒等辅助灌注措施快速成桩的施工技术。该技术成功解决了在复杂地质地区塌孔严重、成孔难、混凝土损耗大等难题,从时间上缩短了单桩施工周期,从材料上减少了混凝土的损耗,大大提升了机械化施工作业水平,降低了施工安全风险,快速提高了桩基施工成桩率,为类似复杂地质条件下的超长桩基施工提供借鉴与参考。

Based on the construction of an ultra long pile foundation for a light rail project in Liuzhou,this paper introduces the construction technology of a full sleeve full rotation drilling rig in a complex geological area where karst is extremely developed and prone to collapse.By building a double steel beam platform to stabilize the full rotation drilling rig,driving a steel sleeve welded with an alloy blade at the bottom to follow up throughout the entire process and form a protective wall,cooperating with a rotary excavator to quickly extract soil and form holes in its hole,and using auxiliary grouting measures such as steel cage wrapped with steel wire mesh or permanent steel casing to quickly form piles,this technology has successfully solved the problems of severe collapse,difficulty in drilling,and high concrete loss in complex geological areas.It has shortened the construction period of single piles in terms of time,reduced the loss of concrete in terms of materials,greatly improved the level of mechanized construction operations,reduced construction safety risks,and rapidly increased the pile completion rate of pile foundation construction.It provides reference and guidance for the construction of ultra long pile foundations under similar complex geological conditions.