岩土工程学报2026，Vol.48Issue(6)：1163-1177,15.DOI:10.11779/CJGE20250881
开口双壁管桩静压沉桩机理及竖向承载特性模型试验研究
Model test investigation into jacking mechanism and bearing characteristics of open-ended double-wall piles
摘要
Abstract
A comprehensive understanding of the pile-soil interaction mechanism during the jacking process of open-ended pipe piles is essential for accurately calculating their vertical bearing capacity.Traditional methods for assessing such piles are unable to distinguish between internal and external soil resistances.This paper introduces the design of an open double-wall pipe pile that enables the independent measurement of internal and external soil resistances.Large-scale model tests are conducted to investigate the cyclic penetration behavior of this pile type in sandy soil foundations with a relative density(Dr)of approximately 50%.This study employs monitoring techniques,including Fiber Bragg Grating(FBG)strain sensors,to examine the variation patterns of soil plug characteristics,internal pile forces,local lateral friction resistances both inside and outside the pile,and pile driving resistances—specifically soil plug resistance,annular resistance,and base resistance—during cyclic penetration processes.Subsequently,a 10-day static compression load test is conducted.Research indicates that ①In the initial penetration phase of open-ended pipe piles,the soil plug height may surpass the penetration depth,indicating that the incremental filling ratio(IFR)exceeds 1.②The local shaft resistance of both the inner and outer pipes gradually decreases with an increasing h/R ratio,demonstrating a pronounced h/R effect.At an h/R ratio of 2.3,the local shaft resistance of the inner pipe is approximately four times greater than that of the outer pipe.③There is a significant correlation between soil plug resistance and the incremental filling ratio(IFR),where higher IFR values correspond to lower soil plug resistance.In contrast,the normalized annular resistance remains largely independent of IFR and maintains a stable value.The normalized base resistance(qb/qc)gradually decreases as the IFR value increases.When the IFR approaches 0,the normalized base resistance(qb/qc)approaches 1,indicating that the base resistance qb becomes nearly equal to the cone resistance qc.④Based on the correlation between normalized base resistance and the effective area ratio,a formula for calculating the base resistance during jacking of open-ended pipe piles was established and validated.It is recommended to consider the influence of different driving methods in bearing capacity calculations.关键词
开口双壁管桩/大比尺模型试验/FBG应变传感器/土塞效应/承载力Key words
open-ended double-wall pipe piles/large-scale model testing/FBG strain sensors/soil plugging effects/load-bearing capacity分类
建筑与水利引用本文复制引用
朱怀龙,朱碧堂,罗如平,王志安..开口双壁管桩静压沉桩机理及竖向承载特性模型试验研究[J].岩土工程学报,2026,48(6):1163-1177,15.基金项目
国家自然科学基金项目(52020105003,52208343)This work was supported by the National Natural Science Foundation of China(Grant No.52020105003,52208343). （52020105003,52208343）
