施工工艺对成桩前期桩基承载力影响分析  

Analysis on the impact of construction technique to bearing capacity of pile foundation in pile forming stage

作　　者：牛富生[1] 郭文明[2] 郭永建[1] 张洪波 

机构地区：[1]同济大学土木工程学院,上海200092 [2]台州市交通勘察设计院,浙江台州317700 [3]宁波顺和路桥设计有限公司,浙江宁波315105

出　　处：《工程勘察》2013年第5期16-22,共7页Geotechnical Investigation & Surveying

摘　　要：根据桩基现场原位试验,对比分析了旋挖钻成孔和正循环钻成孔两种施工工艺对成桩前期桩基承载力性状的影响。试验结果表明:旋挖钻成孔消除了桩侧泥皮的影响,改善了桩的荷载传递性能,使桩侧摩阻力增加,轴力衰减速度加快;旋挖钻成孔桩的桩侧最大摩阻力提高30%以上,达到桩侧最大摩阻力时的沉降约为正循环钻成孔桩的50%;旋挖钻成孔消除了桩端沉渣的影响,其最大端阻力提高136%,相同沉降量下旋挖钻成孔桩桩端阻力提高较大;旋挖钻成孔对桩侧阻力及桩端阻力的综合影响提高了桩的极限承载力。According to the data from in-situ tests, the comparative analysis on the impact of construction technique including the positive circulation craftwork and the bored holes by churning drive to the bearing capacity of pile foundation in pile forming stage is carried out. The test results show that the bored piles by churning drive have eliminated the influence of the mud cakes by the side of the pile; the property of the pile load transmission has be improved, the skin friction of the pile is increased, and the decay rate of the axial force is increased; the maximum skin friction of the bored piles by churning drive is increased about 30% , the settlement of the maximum skin friction is about 50% of the settlement from positive circulation craftwork; the bored piles by churning drive have eliminated the influence of dregs at pile tip and the tip resistance of the pile is increased about 136% , and it is increased rapidly at the same settlement; the integrated influence of the bored piles by churning drive on the skin friction and the tip resistance can greatly increase the ultimate bearing capacity of the piles.

关 键 词：桥梁工程 钻孔灌注桩 旋挖钻成孔 承载力 原位试验 

分 类 号：TU473.1[建筑科学—结构工程]