基于监测结果的快速反馈分析在上海虹源盛世工程中的应用

Application of Monitoring Results Based Fast Feedback Analysis in Extra-large Deep Excavation Engineering

针对虹源盛世超大深基坑工程复杂多样的围护结构、各向异性非均质软土地层、复杂施工工况及卸载形式等综合条件下,土体等效参数位移反分析难题,采用FEM与Nelder-Mead优化反演相结合方法,在扰动位移监测数据的基础上,通过目标参数和误差控制函数条件下的优化迭代拟合,快速反演获得工程区域土体等效弹性参数并将反演结果用于基坑后续工序的扰动位移及稳定性预测计算。结果表明,该方法可以有效避免FEM反问题计算的复杂性和收敛的不确定性,获得更加符合工程场地实际的等效力学参数,提高后续工程扰动位移场及技术风险预测的准确性和可靠性。

The extra-large deep excavation of Hongyuan Shengshi Building Project is featured with several retaining structures, anisotropic and inhomogeneous soft soil, complicated construction and unloading conditions. It is difficult to make the displacement back analysis of equivalent geo-mechanical parameters. Based on the displacement monitoring data, the equivalent elastic parameters of soil are obtained through fast inversion by use of the FEM and Nelder-Mead optimization method. And the inversion results are used for the prediction of disturbance displacement and stability in the later excavation. The engineering practice demonstrates that the FEM combined Nelder-Mead method can avoid the complexity of FEM calculation and uncertainty of convergence, achieve more accurate equivalent geo-mechanical parameters and improve the accuracy and reliability of predicting engineering disturbance displacement field and risk.