应用正交试验设计进行数值模型参数的敏感性分析

Parameter sensitivity analysis of numerical model by cross test design technique

结合深基坑重力式挡土墙侧向变形的有限元分析 ,提出了采用正交试验设计及其统计分析方法研究数值模拟结果对岩土参数敏感性的步骤。该方法能够区分影响计算结果的主要参数和次要参数 ,并对参数的敏感程度进行量化。实例分析表明 ,模拟结果只对个别参数的变化比较敏感 ,而其它参数对模拟结果影响较小。敏感性分析结果符合工程实践经验 ,表明该方法是可行的。

Parameter estimation is one of the key questions in numerical modeling. Combining the FEM modeling of lateral deformation of earth-retaining wall of foundation pit, cross test design technique is used in the sensitivity analysis of mathematical simulation. A procedure is developed to identify the principal and secondary parameters that affect the modeling result, and to analyze and quantify the influence extent of each parameter. The case study indicates that the modeling result is sensitive to only a few parameters; while the variance of some model parameters doesn't cause much difference in the computation result. The results of sensitivity analysis are in accordance with the geotechnical engineering practice.