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蒋    坤¹ , 李盛南^2,3 , 刘新喜¹ , 吴    岩⁴ , 马宸桢¹

 

(1. 长沙理工大学 土木工程学院 , 长沙   410114; 2. 湖南工程学院 建筑工程学院 , 湘潭    411104;

3. 长沙理工大学 道路灾害防治及交通安全教育部工程研究中心 , 长沙   410114;

4. 长沙核工业工程勘察院有限公司 , 长沙   410000)

摘  要: 为探究炭质泥岩基坑湿化变形规律 , 以株洲枫溪大道  (608 所) 基坑工程为研究对象 , 通过不同含水率炭质泥岩的三轴试验获得应力应变曲线 , 研究了炭质泥岩本构模型 , 并利用 FLAC 3D 软件对炭质泥岩基坑湿化前 、后变形进行数值模拟 , 探究了炭质泥岩基坑开挖湿化前 、后的支护桩水平位移 、周边地表沉降变形规律 , 探讨了炭质泥岩湿化后支护桩的桩径 、桩距和锚索预应力对桩身水平位移 、地表沉降的影响分析 。结果表明 : 采用邓肯-张 EB 模型可以较好的描述炭质泥岩本构模型 ; 基坑桩身水平位移呈先增大后减小趋势 , 地表沉降曲线呈“ 勺 ”状且具有明显的空间性 ; 炭质泥岩湿化后基坑变形明显增大 , 桩身水平位移 、周边地表沉降分别增大约 67. 4%、51. 4% ; 炭质泥岩基坑湿化后桩径的改变对基坑变形影响较大 , 桩间距与锚索预应力影响较小 , 选取桩径 1 m, 桩间距 1. 4~ 1. 6 m, 锚索应力 0. 8~ 1. 0F 较为合适 。研究成果可为同类型工程设计提供参考。

关键词: 炭质泥岩 ; 基坑开挖 ; 邓肯-张 EB 模型 ; 湿化变形 ; 数值模拟

中图分类号: TU452      文献标志码: A      文章编号: 1005-8249 (2026) 05-0043-08

DOI:10. 19860/j. cnki. issn1005-8249. 2026. 05. 007

 

JIANG Kun¹ , LI Shengnan^2,3 , LIU Xinxi¹ , WU Yan⁴ , MA Chenzhen¹

(1. School of Civil Engineering, Changsha University of Science & Technology, Changsha 410114, China;

2. School of Architectural Engineering, Hunan Institute of Technology, Xiangtan 411104, China;

3. Engineering Research Center of Catastrophic Prophylaxis and Treatment of Road and Traffic Safety of Ministry of Education, Changsha University of Science & Technology, Changsha 410114, China;

4. Changsha Nuclear Industry Engineering Survey Institute Co. , Ltd. , Changsha 410000, China)

Abstract : In order to explore the deformation law of carbonaceous mudstone foundation pit, taking the foundation pit project of Fengxi Avenue (608 Institute) in Zhuzhou as the research object, the stress - strain curve of carbonaceous mudstone with different moisture content was obtained through triaxial test, the constitutive model of carbonaceous mudstone was studied, and the deformation of carbonaceous mudstone foundation pit before and after wetting was numerically simulated by FLAC 3D software, an investigation was conducted into deformation law of supporting pile horizontal movement, peripheral surface settlement , both prior to and subsequent to the excavation of a carbonaceous mudstone foundation pit that underwent wetting, and the influence of pile diameter, pile spacing and anchor cable prestress on pile horizontal displacement and surface settlement after wetting of carbonaceous mudstone foundation pit was discussed.  The results show that Duncan - Chang EB model can better describe the constitutive model of carbonaceous mudstone; The results show that the vertical displacement of the pile body of the base pit increases first and then decreases.  The surface settlement curve is "  spoon "  shaped and has obvious spatial characteristics; The results indicate a significant increase in the deformation of the foundation pit following the wetting of carbonaceous mudstone. Specifically, the horizontal displacement of the pile body and the settlement of the neighboring land surface have risen by 67. 4% and 51. 4% , respectively; The wetting of the carbonaceous mudstone foundation pit significantly affects the deformation of the pit through changes in pile diameter, whereas the impacts of pile spacing and anchor cable prestress are relatively minor. It is more appropriate to select pile diameter of 1 m, pile spacing of 1. 4~ 1. 6 m and anchor cable stress of 0. 8~ 1. 0F. The research findings can serve as a valuable reference for similar engineering design projects.

Key words: carbonaceous mudstone; foundation pit excavation; Duncan - Chang  EB  model;  wetting  deformation; numerical simulation

  项目来源 : 国家自然科学基金资助项目 (52108405, 51674041) ; 湖南省自然科学基金资助项目 (2022JJ40122, 2022JJ50117)。

作者简介 : 蒋  坤 (1999—) , 男, 硕士研究生, 研究方向 : 岩土。

收稿日期 : 2025-01-10