近年来，我国高层建筑地基基础多采用各种桩基、箱基或混合复配形式，其中大直径钻孔灌注桩又以施工技术先进、适应性强、质量好、成本低而受到重视。去年我队在粘土层、砂土层、砂层等较松软地层的基础施工中运用了振冲成孔灌注桩技术。振冲法在软弱地基的砂桩、碎石桩、石灰桩施工中具有设备简单、搬迁方便，成孔速度快等优点。但这种施工方 In recent years, high-rise building foundations in China have adopted a variety of pile foundations, box foundations or mixed compounding forms. Large-diameter cast-in-place bored piles have received attention due to their advanced construction technology, strong adaptability, good quality, and low cost. Last year, the team used vibro-punched perforated pile technology in the foundation construction of clay, sand and sand layers and other softer formations. The vibroflotation method has the advantages of simple equipment, convenient relocation, quick hole formation, etc. in the construction of sand piles, gravel piles and lime piles in soft foundations. But this construction side