一、概括目前我国桥梁桩基施工大部分是采用钻孔灌注桩施工工艺,该施工方法具有许多优点。自1965年开始在全国逐渐推广,数年间几乎成了各种桥梁基础的首选方案,尤其是改革开放的20年间,道路桥梁建设突飞猛进,钻孔灌注桩技术在理论和工艺上也获得了长足的发展。然而在某些条件下 I. General At present, most of the construction of bridge pile foundation in our country adopts the bored pile construction technology, and the construction method has many advantages. Since 1965, it has been gradually popularized in the whole country and has almost become the first choice plan for various bridges during the past few years. Especially during the two decades of reform and opening up, the construction of road and bridge has progressed by leaps and bounds. The technology of bored piles has also gained a great deal of theory and technology development of. However under certain conditions