软土地区大直径中掘扩底法管桩承载性能现场试验分析  

Experimental study on load-bearing behavior of large-diameter belled PHC pipe pile by NAKS-construction-method in soft soil area

作　　者：李志刚[1,2] 张雁[1,3] 朱合华[1,4] 侯玉宾[5] 赵春风[1] 

机构地区：[1]同济大学土木工程学院,上海200092 [2]上海市政工程设计研究总院(集团)有限公司,上海200092 [3]建华管桩集团有限公司,江苏句容212413 [4]同济大学岩土及地下工程教育部重点实验室,上海200092 [5]河海大学,江苏南京210098

出　　处：《土木工程学报》2016年第9期78-86,共9页China Civil Engineering Journal

摘　　要：基于软土地区大直径中掘扩底法管桩静载荷试验，分析软土地区大直径中掘扩底法（简称中掘法）管桩承载特性，研究成果表明：在等桩径等桩长条件下，中掘扩底法管桩的单桩极限承载力较常规锤击法管桩低10％左右，但较钻孔灌注桩可提高30％以上；中掘法管桩桩顶荷载沉降曲线均呈现缓降型，单桩竖向桩基极限承载力应根据桩顶沉降量确定；在桩顶达到极限承载力时，中掘法管桩桩端阻力有明显提高，桩端阻力可占桩顶荷载40％-50％，呈现为端承摩擦桩，竖向承载能力得到明显提高。文中研究成果可为软土地区大直径中掘扩底法管桩的理论研究和工程应用提供参考价值。Based on the in-situ load tests, the load-bearing behavior of large-diameter belled PHC pipe piles by NAKS- construction-method in soft soil area is studied. In case of the same pile radius and the pile length, the ultimate bearing capacity of the large-diameter belled PHC pipe piles accounts for that of the hammer piles 90%, and is 1.3 times larger than that of the bored piles. The results show that the load carrying curves of most piles vary gradually, and the ultimate bearing capacity of the piles is determined by the displacement of the pile head. About 40% - 50% of the loads at pile tips is shared by the axial force at pile top under the ultimate bearing capacity. The piles behave as end-bearing friction ones, and the ultimate bearing capacity is higher. The research results can provide reference for the research and application of large-diameter belled PHC pipe pile by NAKS-construction-method in soft soil area.

关 键 词：大直径 中掘扩底法管桩 极限承载力 端承摩擦桩 

分 类 号：TU447[建筑科学—岩土工程]