首页|囊体扩张主动控制桩基水平变形机理分析

囊体扩张主动控制桩基水平变形机理分析

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囊体扩张是一种新型地下结构变形主动控制技术,然而其在桩基变形控制机理方面尚未深入研究.采用有限元软件探究了囊体扩张控制桩基水平变形机理,分析了囊体扩张引起桩基和土体变形特性以及囊体-土体-桩体之间相互作用.结果表明:扩张直径0.5 m的囊体对直径为1.2 m的桩可产生最大5.5 mm水平变形,控制效率为60%,囊体扩张对桩基水平变形控制效果良好.囊体扩张会引起邻近土体产生较大的超孔隙水压力,而孔压消散会导致土体压缩而降低桩基控制效率.当扩张距离较小时,桩径对囊体扩张控制效果影响显著.囊体扩张对桩径为 0.4~1.6 m的桩均有一定的变形控制效果,尤其适用于小直径桩基的变形控制.随扩张直径的增大,桩基最大水平位移近乎呈线性增大.此外,桩基水平变形随扩张距离增大而减小,但由于扩张对周围孔隙水压力影响范围有限,导致控制效率呈增大趋势.双排囊体扩张控制变形中"遮拦效应"和"反力效应"明显,控制桩基变形应遵循"先远后近,逐排扩张"的原则,以提高控制效果.
Horizontal deformation of piles controlled by capsule expansion technique
The capsule expansion technique(CET)is a new active deformation control technology,but its mechanism of deformation control of pile foundation has not been thoroughly studied.Numerical analysis is performed to explore the control effects of capsule expansion on horizontal deformation of piles.The deformation characteristics of piles and soils and the interaction among the capsules,soils and piles are further analyzed.The results show that the maximum horizontal deformation of 5.5 mm,is induced by the CET with expansion diameter of 0.5 m,and the control efficiency is 60%.The CET leads to a large excess pore water pressure of the adjacent soils.The dissipation of the excess pore water pressure causes the soils to be compressed under the additional stress.When the expansion distance is small,the pile diameter presents a significant impact on the capsule expansion.The expansion has certain deformation control on the piles with a diameter of 0.4~1.6 m,especially suitable for deformation control of small-diameter pile foundations.As the expansion diameter increases,the maximum horizontal displacement of the pile foundation increases almost linearly.In addition,the horizontal displacement of the pile decreases as the expansion distance increases.However,due to the limited influences of expansion on the surrounding pore water pressure,the control efficiency shows an increasing trend.The"blocking effect"and"reaction effect"are obvious in the deformation control of the double-row capsule expansion.The principle of"far first and then near,row by row expansion"should be followed to improve the control effects in controlling deformation of pile foundations.

capsule expansion techniquepiledeformation controlmechanism analysis

黄建友、闫宇涛、刁钰、郑刚、李凯、贾建伟、刘永超

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天津大学建筑工程学院,天津 300072

滨海土木工程结构与安全教育部重点实验室(天津大学),天津 300072

中国建筑第五工程局有限公司,湖南 长沙 410004

中国建筑第六工程局有限公司,天津 300457

天津建城基业集团有限公司,天津 300301

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囊体扩张 桩基 变形控制 机理分析

2025

岩土工程学报
中国水利学会 中国土木工程学会 中国力学学会 中国建筑学会 中国水力发电工程学会 中国振动工程学会

岩土工程学报

北大核心
影响因子:1.952
ISSN:1000-4548
年,卷(期):2025.47(1)