徐宇国      （宁波市建筑设计研究院 315012）

[提要]  通过对场地以下8m左右有较密大直径钻孔灌注桩的改建工程基础方案的分析比较，提出了双层地基模式的概念。工程实践中采用了水泥搅拌桩加固处理基础与深层长桩间的土体的方法，取得了较好的效果。
[关键词]  水泥搅拌桩  双层地基  改建工程

The foundation plan of a reconstruction project is analyzed and compared in which the high density large diameter boring agitating piles is under the ground about eight meters. The conception of double layer groundsill model is put forward. A method of dealing with soil between foundation and deep long pile by cement mixing pile is used. The process of design is expounded also. It is effective and valuable for practical engineering.
Keywords: cement mixing pile; double layer groundsill; reconstruction engineering