王  旭  于志强
    （西南交通大学地下与岩土工程系  成都 610031）

[提要]  对压密灌浆法用于桩底灌浆提高钻孔灌注桩承载力的工艺和机理进行了探讨。分析了压密灌浆和普通灌浆的异同以及桩底压密灌浆钻孔桩的承载力特性，并给出了桩端持力层为粗颗粒土的压密灌浆钻孔桩的极限承载力经验公式。
[关键词]  压密灌浆 钻孔灌注桩 承载力

Technology and mechanism of compaction grouting used in bored pile base grouting to enhance the bearing capacity are discussed. By comparison, the authors pointed out the difference between compaction grouting and common grouting method used in bored pile base grouting. The feature of bored pile with compact toe is discussed and empirical formula of dtimate bearing capacity of bored pile when its toe is in coarse grained soil is proposed.
Keywords: compacrion grouting; bored filling pile; bearing capacity