长江科学院院报2025，Vol.42Issue(9)：139-146,8.DOI:10.11988/ckyyb.20240798
土体参数竖向变异性对隧道开挖引起邻近桩基竖向响应的影响
Effect of Vertical Variability of Soil Parameters on Tunnelling-Induced Vertical Responses of Adjacent Pile Foundations
摘要
Abstract
[Objective]Accurate prediction of tunnelling-induced vertical responses in pile foundations remains a critical challenge in urban underground construction.Traditional deterministic analyses of the complex tunnel-soil-pile interactions often assume homogeneous soil properties,neglecting the inherent spatial variability of soil proper-ties.Such simplifications may result in underestimating or misrepresenting pile responses.To bridge this gap,the primary objective of this study is to develop and implement a sophisticated probabilistic model capturing the vertical spatial variability of soil properties.This model aims to facilitate a comprehensive stochastic analysis and provide more realistic and reliable predictions of pile behavior due to adjacent shield tunnel excavation.[Methods]The core deterministic framework employed a well-established two-stage analytical procedure:first,tunnelling-induced free-field ground movements were modeled using the Loganathan-Poulos solution,which accounted for volume loss and tunnel geometry effects on surrounding soils;second,pile foundation responses to these soil displacements were evaluated through Load Transfer Analysis to calculate pile head settlements and axial force distributions along the pile shaft.Undrained shear strength was modeled as a random field to account for the vertical spatial variability.The two-stage deterministic procedure and the vertical random field model for undrained shear strength were integrated within an automated Monte-Carlo simulation framework,which constituted the developed stochastic Two-Stage Anal-ysis model.After a sufficiently large number of iterations,the recorded pile responses were statistically analyzed,yielding the probability distributions,mean values,and standard deviations for the pile head additional settlement and the maximum additional axial force along the pile shaft.[Results]Both the coefficient of variation and the cor-relation length of the undrained shear strength exerted a significant influence on the statistical moments of the pile responses.An increase in the coefficient of variation generally led to higher mean values of pile head additional set-tlement and the mean maximum additional axial force.The correlation length caused significant variations in both the mean and,particularly,the standard deviations of pile settlements and axial forces compared to the homogene-ous case.The probability of pile head additional settlement exceeding a critical serviceability limit state showed a strong dependence on the vertical spatial variability of soil strength.As the overall variability increased,the compu-ted probability of settlement failure rose significantly.The detrimental impact of soil spatial variability on pile relia-bility amplified by higher levels of deterministic loading factors.Increased ground deformation caused by larger tun-nel volume loss intensified the negative effects of soil variability.In addition,existing structural loads applied to the pile head further magnified the sensitivity of pile responses and the associated failure probability to the underlying soil uncertainty.Essentially,the combined loading conditions made the pile foundation more vulnerable to the ad-verse consequences of spatially variable soil properties.[Conclusion](1)The proposed stochastic two-stage model successfully bridges the gap between conventional analytical methods and real-world soil heterogeneity.(2)The de-veloped Monte-Carlo automation program can provide practical guidelines for prioritizing vertical variability charac-terization in geotechnical investigations and for adopting probabilistic design methods instead of conventional safety factors.(3)The current model neglects horizontal soil variability and construction disturbances.Future work should integrate 3D random fields with machine learning techniques for enhanced prediction.关键词
隧道开挖/桩基/两阶段分析法/竖向变异性/随机场Key words
tunnel excavation/pile foundation/two-stage analysis method/soil vertical variability/random field modeling分类
建筑与水利引用本文复制引用
王惠民,王耀,李庆文,张静..土体参数竖向变异性对隧道开挖引起邻近桩基竖向响应的影响[J].长江科学院院报,2025,42(9):139-146,8.基金项目
江苏省高等学校自然科学研究项目(19KJB560006,22KJD560007) （19KJB560006,22KJD560007）
科技部国家高端外国专家项目(G2023014042L) （G2023014042L）
江苏省产学研合作项目(BY20231095) （BY20231095）
江苏高校青蓝工程优秀青年骨干教师项目(苏教2021:11) （苏教2021:11）
盐城市基础研究计划项目(YCBK202242) （YCBK202242）
盐城工业职业技术学院自然科学重点课题项目(Ygy1902,Ygy2202) （Ygy1902,Ygy2202）
江苏省高职院校教师企业实践培训项目(2025QYSJ118) （2025QYSJ118）
盐城市自然科学软课题(yckxrkt2025-18) （yckxrkt2025-18）
