地下空间与工程学报2024,Vol.20Issue(1) :311-319.

基坑开挖与承压水突涌对桩基承载力影响分析

Analysis of Influence of Foundation Pit Excavation and Confined Water-Inrush on Pile Bearing Capacity

郭星宇 冯世进
地下空间与工程学报2024,Vol.20Issue(1) :311-319.

基坑开挖与承压水突涌对桩基承载力影响分析

Analysis of Influence of Foundation Pit Excavation and Confined Water-Inrush on Pile Bearing Capacity

郭星宇 1冯世进2
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作者信息

  • 1. 上海勘察设计研究院(集团)有限公司,上海 200093;同济大学地下建筑与工程系,上海 200092
  • 2. 同济大学地下建筑与工程系,上海 200092
  • 折叠

摘要

为研究基坑开挖与承压水突涌对桩基承载力的影响,选取典型工程案例,通过现场水位观测调查含水层分布情况及水位埋深,进行了坑底抗突涌验算,结合现场突涌发生过程,分析了突涌发生的原因.通过原位静力触探试验结果的对比,分析了坑底各土层扰动度以及扰动度随深度的变化规律,并提出了扰动度与桩基设计参数的关系.结果发现:承压水击穿管桩土塞是引起突涌的主要原因;基坑开挖对坑底以下土体的影响深度约6.5 m~9 m,扰动度随深度线性递减;突涌对桩端以上约2 m范围土体强度影响最大,最大扰动度达到0.91,对桩端以下2 m~4 m深度范围土体影响线性递减;承压水突涌对桩基承载力影响远大于基坑开挖对桩基承载力的影响,突涌点位置桩基承载力受到的影响最大,距离突涌点越远影响越小.

Abstract

This paper discusses the influence of foundation pit excavation and inrushing for confined water to pile bearing capacity through a typical engineering case.In this case,the distribution of aquifer and the depth of water level are investigated by field test which are used to calculate and find the causes of inrushing for confined water,combined with the process of inrushing and engineering construction conditions,the causes of inrushing for confined water are found.Then in-situ static cone penetration test is carried out,which is used to find the disturbance depth and extend of soil layers caused by foundation pit excavation and inrushing for confined water,while the relations are suggested between disturbance degree of each soil layer and pile capacity parameters,with this relationship,it is easy to see the disturbance law of these influences.The results show that confined water going through the plug in pipe pile is the main reason of inrushing,the depth of influence of foundation pit excavation on the soil strength below the pit bottom is about 6.5 meters to 9 meters,and the disturbance degree decreases linearly with depth increase.By comparison,the inrushing's influence on the soil strength is much greater than foundation pit excavation,the influence range are from a distance of 2 meters above the pile tip to a distance of 4 meters under the pile tip,and the maximum disturbance degree reaches 0.91.Additionally,the lowest bearing capacity of pile foundation is at the location of inrushing point,the farther away from the inrushing point,the larger bearing capacity can be achieved.

关键词

基坑开挖/承压水突涌/扰动度/桩基承载力

Key words

foundation pit excavation/inrushing for confined water/disturbance degree/bearing capacity of pile foundation

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出版年

2024
地下空间与工程学报
中国岩石力学与工程学会,重庆大学

地下空间与工程学报

CSTPCD北大核心
影响因子:0.886
ISSN:1673-0836
参考文献量11
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