珊瑚砂地基HSCA膨胀桩侧阻提升效应试验研究  

Experimental study on the lateral resistance lifting effect of HSCA expansion piles on coral sand foundation

作　　者：孙涛 陈振勋 刘杰[1,2] 杨渝南[1,2] 庹明民[1] 胡源聂弘 SUN Tao;CHEN Zhenxun;LIU Jie;YANG Yunan;TUO Mingmin;HU Yuanniehong(College of Civil Engineering and Architecture,China Three Gorges University,Yichang,Hubei 443002,China;Badong National Observation and Research Station of Geohazards,China University of Geosciences(Wuhan),Wuhan,Hubei 430074,China)

机构地区：[1]三峡大学土木与建筑学院,湖北宜昌443002 [2]中国地质大学(武汉)湖北巴东地质灾害国家野外科学观测研究站,湖北武汉430074

出　　处：《岩石力学与工程学报》2025年第1期248-260,共13页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金面上项目(52079071);湖北巴东地质灾害国家野外科学观测研究站开放基金(BNORSG202313);三峡库区地质灾害教育部重点实验室开放基金(2020KDZ08)。

摘　　要：海洋环境岛礁工程建设中,桩基础的承载性能往往与珊瑚砂的破碎特性密切相关,明确珊瑚砂颗粒破碎对桩基承载力的影响意义重大。基于此,开展系列HSCA膨胀桩模型试验与现场试验,探究膨胀桩正应力与桩侧珊瑚砂密实度对桩侧摩阻力提升效应的影响。研究结果表明:(1)添加HSCA高强膨胀剂,可显著提升桩侧正应力与桩周珊瑚砂密实度,从而大幅提高桩侧摩阻力与桩体承载力。膨胀剂掺量为15%时,桩体膨胀段极限侧阻力提升了69.7%,整桩极限承载力提高了38.5%。(2)基于颗粒破碎累积应力损失效应,提出考虑颗粒破碎的膨胀桩侧珊瑚砂膨胀应力传递模型,验证分析表明,该模型可较好地反映膨胀应力在珊瑚砂中的传递规律。(3)膨胀桩对桩侧珊瑚砂密实度提升效果显著,桩身自膨胀可有效填充桩侧珊瑚砂由于颗粒破碎产生的体缩空间,强化桩周珊瑚砂地基承载力。(4)建立适用于珊瑚砂地基的膨胀桩侧摩阻力预测模型,并通过现场试验验证了该模型的工程适用性。研究结果可为珊瑚砂地基中膨胀桩施工设计提供参考。The bearing performance of pile foundations in marine environment island and reef engineering construction is often closely related to the fragmentation characteristics of coral sand.It is of great significance to clarify the impact of coral sand particle fragmentation on the bearing capacity of pile foundations.Based on this,a series of HSCA expansion pile model tests and field tests were conducted to explore the effects of the normal stress of the expansion pile and the compactness of the coral sand on the improvement of pile side friction resistance.The research results show that:(1)incorporating HSCA high-strength expansion agent can significantly improve the normal stress on the pile side and the compactness of coral sand around the pile,thereby greatly improving the pile side friction resistance and overall pile bearing capacity.When the expansion agent dosage reaches 15%,the ultimate lateral resistance of the expansion section of the pile increases by 69.7%,and the ultimate bearing capacity of the entire pile increases by 38.5%.(2)Considering the cumulative stress loss effect due to particle breakage,a stress transfer model for the expansion of coral sand on the side of expansion piles considering particle breakage is proposed.Verification analysis demonstrates that the model accurately reflects the transfer law of expansion stress in coral sand.(3)The expansion pile significantly improves the compactness of coral sand on the pile side.The selfexpansion of the pile body effectively fills the shrinkage space in coral sand caused by particle breakage,thereby enhancing the bearing capacity of the coral sand foundation around the pile.(4)A prediction model for lateral friction resistance of expansion piles in coral sand foundations was established and its engineering applicability was verified through field experiments.The findings of this research can serve as a reference for the construction design of expansion piles in coral sand foundations.

关 键 词：桩基工程 颗粒破碎 膨胀桩 膨胀应力传递机制 压缩率 侧阻提升效应 

分 类 号：TU47[建筑科学—结构工程]