新型螺旋挤土灌注桩现场试验研究  

FIELD TEST STUDY OF NEW-TYPE SOIL DISPLACEMENT SCREW PILE

作　　者：李志毅[1,2] 刘钟[1,2] 赵琰飞[1,2] 张慧东[1,2] 

机构地区：[1]中冶建筑研究总院有限公司,北京100088 [2]中国京冶工程技术有限公司,北京100088

出　　处：《岩石力学与工程学报》2011年第2期411-417,共7页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家财政部施工新技术研究与开发项目(财企(2006)376号);住房和城乡建设部科学技术项目(2008–K2–40)

摘　　要：螺旋挤土灌注桩(SDS桩)是一种新型的完全挤土型桩,该桩以其承载力高、施工速度快、对施工场地无污染等特征,已在多个国家得到应用,但国内还没有应用该桩型的工程实例。为此,在北京一工地进行2次SDS桩现场试验,研究SDS桩成桩时的挤土效应、承载特性和桩侧摩阻力分布规律及SDS桩与长螺旋灌注桩(CFG桩)承载性状的异同。试验结果表明:SDS桩施工过程中的地表隆起主要发生在成孔开始到螺旋挤扩钻头的挤扩部分全部进入土体阶段,之后地表隆起逐渐趋于稳定;其挤土效应主要在距桩位中心4倍桩径范围内完成,且土体的压缩性越高,挤土范围越大;在相同桩顶沉降量条件下,SDS桩的极限承载力比CFG桩提高30%～50%。Due to the high bearing capacity,high productivity of installation and non-pollution on site,such soil displacement screw（SDS） pile has been widely applied in many countries. But there is no successfully engineering application report in China yet. To study soil compaction effect,bearing characteristics,distribution of side friction resistance of SDS pile and the difference between SDS pile and cement flyash gravel（CFG） pile,two field tests are carried out in a site in Beijing. Test results show that the surface vertical displacement during construction is mainly completed from the beginning of auger drilling to the auger′s compaction part squeezing into the soil wholly;then the surface vertical displacement tends to stabilize. The soil compaction effect is mainly completed within 4 times the pile diameter;and the higher the soil compressibility is,the larger the soil compaction scope is. The ultimate bearing capacity of SDS pile can be increased by 30%-50% compared with CFG pile at the same settlement of the pile top.

关 键 词：桩基工程 螺旋挤土灌注桩(SDS桩) 挤土效应 桩侧摩阻力 现场试验 承载特性 

分 类 号：TU473[建筑科学—结构工程]