钻孔扩底灌注桩的设计与检测  

DESIGN AND INSPECTION OF UNDER-REAMED BORED PILE

作　　者：韩建强[1] 宋庆东[1] 杨明[2] 

机构地区：[1]广州市设计院,广州510620 [2]中科院广州化灌工程有限公司,广州510070

出　　处：《地质与勘探》2003年第4期90-91,94,共3页Geology and Exploration

摘　　要：结合钻孔扩底灌注桩在某高层建筑物基础中的成功应用,对钻孔扩底灌注桩的成桩原理进行了有关的阐述,认为扩底钻头的扩张角α≤25°为宜,且扩底高度范围内岩石层的饱和单轴抗压强度标准值一般不大于6MPa;同时在单桩竖向承载力的设计计算时,要求对桩身侧阻力与桩底端阻力进行相应修正。为确保钻孔扩底灌注桩桩端扩大头的施工质量,根据其自身特点,提出采用传统的钻孔取芯法进行检测,并针对工程应用情况进行了定性评价。According to successful application of bored pile in a tall building, construction principle of under-reamed bored pile is discussed in details. It is thought that the reaming-angle of reaming bit should be less than 25 degree, the rock compression strength under the pile end should be no more than 6MPa, and lateral frictional force and end resistance of pile should be adjusted when vertical carrying capacity is calculated. A simple and traditional method borehole sampling is suggested to knowledge the quality on enlarged-end of pile according to its characteristic, and the qualitative analysis is given in connection with engineering application.

关 键 词：钻孔扩底灌注桩 竖向承载力 桩身侧阻力 桩底端阻力 

分 类 号：TU431[建筑科学—岩土工程]