华南理工大学学报(自然科学版) ›› 2025, Vol. 53 ›› Issue (10): 86-96.doi: 10.12141/j.issn.1000-565X.240593

• 土木建筑工程 • 上一篇    下一篇

干湿循环和施工振动下残积土的强度变形及应用

陈东霞1, 唐佳润1, 王东东1, 陈波2, 张婧怡1   

  1. 1.厦门大学 建筑与土木工程学院/福建省滨海土木工程数字仿真重点实验室,福建 厦门 361005
    2.中铁南方投资集团有限公司,广东 深圳 518000
  • 收稿日期:2024-12-20 出版日期:2025-10-25 发布日期:2025-05-26
  • 作者简介:陈东霞(1976 —),女,博士,助理教授,主要从事残积土工程特性、基坑工程、边坡工程及地基处理研究。E-mail: dongxiachen@xmu.edu.cn
  • 基金资助:
    福建省自然科学基金项目(2021J01010);福建省自然科学基金项目(2021J02003);中铁南方2022年科技创新计划课题(202208);厦门市科技局项目(2024CXY0115)

Strength-Deformation Behavior and Engineering Applications of Residual Soil Under Drying-Wetting Cycles and Construction Vibration

CHEN Dongxia1, TANG Jiarun1, WANG Dongdong1, CHEN Bo2, ZHANG Jingyi1   

  1. 1.School of Architecture and Civil Engineering/Fujian Key Laboratory of Digital Simulations for Coastal Civil Engineering,Xiamen University,Xiamen 361005,Fujian,China
    2.China Railway Southern Investment Group Co. ,Ltd. ,Shenzhen 518000,Guangdong,China
  • Received:2024-12-20 Online:2025-10-25 Published:2025-05-26
  • About author:陈东霞(1976 —),女,博士,助理教授,主要从事残积土工程特性、基坑工程、边坡工程及地基处理研究。E-mail: dongxiachen@xmu.edu.cn
  • Supported by:
    the Natural Science Foundation of Fujian Province(2021J01010)

摘要:

在干湿循环和施工振动共同作用下,残积土的强度和变形参数将发生显著劣化,对基坑工程的安全产生影响和威胁。借助直剪和固结试验获得残积土在干湿循环和施工振动作用下强度和变形的规律及劣化后参数预测模型,并将其应用于某地铁基坑开挖精细化数值模拟。试验分析发现:黏聚力c随干湿循环次数n和振动时间t的增加呈非线性衰减,内摩擦角φn增加呈波动上升,振动作用对φ的影响随n增加而减小;未经历振动时随n增加,压缩系数av1-2呈线性增长,参考切线模量Eoedref缓慢减小;经历振动后av1-2呈波动变化,Eoedref先快速减小、再缓慢减小、最后逐渐增大。考虑干湿循环和施工振动影响将基坑划分为6个影响区:干湿循环充分影响区、干湿循环影响过渡区、干湿循环和振动共同强影响区、干湿循环和振动共同弱影响区、仅振动影响区和无影响区。在各个区采用劣化后对应的土体参数开展基坑开挖精细化数值模拟,结果表明:随基坑边缘距离增大,地表沉降呈“先减小后增大”的变化趋势。随基坑深度增加,地下连续墙水平位移呈“两头小、中间大”的变化趋势;对于地表沉降和地下连续墙水平位移,有建筑物一侧的变形均小于无建筑物一侧的变形。考虑干湿循环和施工振动共同作用后的地表沉降、地下连续墙水平位移模拟结果更接近现场监测值,可为残积土基坑设计施工提供有效技术指导。

关键词: 残积土, 干湿循环, 振动, 强度, 变形, 数值模拟

Abstract:

Under the coupled effects of drying-wetting cycles and construction vibration, both strength and deformation parameters of residual soil undergo significant degradation, thereby compromising the safety of excavation support systems. Through direct shear tests and consolidation tests, this study characterizes the strength-deformation behavior of residual soil under drying-wetting cycles and construction vibration, develops predictive models for deteriorated parameters, and implements them in high-fidelity numerical simulations of a metro excavation project. The experimental results indicate that: cohesion c undergoes nonlinear decay with increasing drying-wetting cycles n and vibration duration t; internal friction angle φ exhibits oscillatory increase with n, while vibration effects on φ diminish progressively at higher n; without vibration, compression coefficient av1-2 increases linearly with n, whereas reference tangent modulus Eoedref decreases gradually; under vibration, av1-2 shows triphasic evolution: rapid initial decrease slow secondary decrease eventual increase. By considering the effects of drying-wetting cycle and construction vibration, the excavation is divided into 6 impact zones: fully drying-wetting-affected, over drying-wetting-affected, strongly coupled drying-wetting and vibration, weakly coupled drying-wetting-affected, vibration-only, and unaffected. Degraded soil parameters corresponding to each impact zone were implemented in high-fidelity numerical simulations of the excavation sequence. Results reveal that surface settlement first decreases then increases with horizontal distance from the excavation edge. As the excavation depth increases, diaphragm wall horizontal displacement exhibits a “small-large-small” profile along the wall height. Both ground settlement and wall horizontal displacement are consistently smaller on the side adjacent to an existing building than on the unobstructed side. Incorporating the coupled effects of drying and wetting cycling and construction vibration, the simulated surface settlements and wall horizontal displacements match the field measurements more closely, thus providing a practical guidance for the design and construction of the residual soil excavations.

Key words: residual soil, drying-wetting cycle, vibration, strength, deformation, numerical simulation

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