复杂地层冲击反循环成孔工艺

Pile Hole Conshuchon Technique in Complicated Formation

在上部为软粘土，下部为涤厚砂砾石的复杂地层中施工，综合采用冲抓十冲击反循环成孔工艺可以取得较好的钻进效率。本文着重介绍了反循环冲击钻进在深厚卵砾石地层中的施工技术。

Grab drilling method is efficial and economical in shallow soft clays.Reverse impact drilling in bouldery formation is a new hopeful technique.The writers indroduce us some experience of this technique in the paper