通过有限元模型的代理分析模型计算,形成涵盖围护结构深层水平位移与土体参数的样本库,并基于最小二乘支持向量机(least square support vector machine,LSSVM)的智能反演算法,建立围护结构深层水平位移与土体参数的关系;再通过现场监测数据,对土体参数进行反演修正,形成了随基坑开挖过程的逐工况反演反馈模型,分析了施工开挖步骤对土体参数的影响规律,并结合相应规范取值,探讨了水平抗力系数的取值范围,进而分别通过弹性地基梁法和有限元法,针对围护桩结构的变形进行了分析与预测.结果表明:基于逐工况的反演分析方法可以有效地预测围护结构的变形,对于大型深基坑的安全施工有很好的指导意义.
Analysis and discussion on deformation of foundation pit retaining structure based on one-by-one working condition inversion
In this study,a sample library covering the deep horizontal displacement of the retaining structure and soil parameters is formed through the proxy analysis model calculation of the finite element model.Based on the intelligent inversion algorithm of least square support vector machine,the relationship between the deep horizontal displacement of the retaining structure and soil parameters is established.On-site monitoring data is then used to retrieve and correct the soil parameters to form a one-by-one working condition inversion feedback model with the excavation process of the foundation pit.The law of the influence of construction and excavation steps on soil parameters is analyzed,and the values are determined according to the corresponding specifications.The study also discusses the value range of the horizontal resistance coefficient,and analyzes and predicts the deformation of the retaining pile structure by elastic foundation beam method and finite element method respectively.The results demonstrate that the inversion analysis method based on case by case can effectively predict the deformation of the retaining structure,and thus has a good guiding significance for the safe construction of large deep foundation pits.
deep foundation pitparameter inversionorthogonal designfinite element methodelastic foundation beam method
NETL
NSTL
万方数据
