李运城    胡照勇
    （安阳市建筑设计研究院 455000）

[提要]  根据对堆载预压经验公式的研究及多年设计经验，结合疏桩设计理论，提出了在没有新的地质资料的情况下，如何利用原基础合理确定挖扩桩桩距和桩径。
[关键词]  基础  疏桩设计加层改造

Based on the research of pile up load prestressed experience formula and the designing experience, combining the designing theory of the rarely distributed pile, the authors presents how to reasonably determine the pile's distance and diameter with bulb shaped base in site on the original building base without knowing the new geological information.
Keywords:  masonry structure; original foundation; rarely distributed pile; reforming