基于优化反分析的深基坑变形超前智能预测方法

    Intelligent Prediction of wall deflection and settlement in deep excavation using Optimization-based Back Analysis method

    • 摘要: 深基坑开挖过程中的高精度变形预测是保障工程安全的关键环节。为实现基坑开挖诱发地下连续墙变形与地表沉降的精准预测,本研究创新性地构建了一种基于优化反分析技术的智能超前预测框架。该框架通过建立“监测-反演-预测”的滚动闭环系统实现动态预报:首先基于已完成开挖阶段的监测数据,运用优化算法动态反演土体本构参数;继而利用优化参数对后续未开挖阶段进行变形预测,如此循环迭代直至工程竣工。本预测框架具有以下技术特征:采用改进回溯搜索算法(MBSA-LS),以监测数据与数值模拟结果的偏差构建损失函数;基于OPTUM G2商业有限元平台实现开挖过程的分步模拟;选用考虑小应变特性的硬化摩尔库伦(HMC)本构模型,准确刻画软土在卸荷条件下的力学响应。为验证方法的可靠性,研究选取两个典型的分阶段开挖工程案例进行实证分析。结果显示该方法不仅为深基坑工程的安全控制提供了有效的技术手段,其前瞻性预测特性更可为施工风险预警提供决策依据,具有重要的应用价值

       

      Abstract: High-precision deformation prediction during deep excavation is critical for ensuring engineering safety. To achieve accurate predictions of excavation-induced diaphragm wall deformation and ground settlement, this study develops an intelligent forward-prediction framework based on optimized back-analysis techniques. The framework establishes a "monitoring-inversion-prediction" rolling closed-loop system to enable dynamic forecasting. Specifically, monitoring data from completed excavation stages are used to identify soil constitutive parameters via optimization algorithms; these optimized parameters are then applied to predict deformations in subsequent unexcavated stages. This process is iterated until project completion. Key technical features include: (1) an inverse analysis method enhanced by differential evolution, where the objective function minimizes the deviation between monitoring data and numerical simulations; (2) stepwise excavation simulation using the finite element software OPTUM G2; and (3) the application of the Hardening Mohr-Coulomb (HMC) model with small-strain stiffness to accurately characterize soft soil behavior under unloading conditions. The method was validated using two typical staged excavation case studies. The results demonstrate strong agreement between predicted and measured data, with accuracy significantly surpassing conventional methods. This approach provides an effective solution for safety control in deep excavations and serves as a valuable decision-making tool for early risk warning

       

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