深基坑墙顶水平变形的灰色-时序动态预测

深基坑墙顶水平变形是一个动态的相互依存的过程。在基坑开挖与施工过程中 ,根据变形观测数据用灰色系统理论与时间序列分析方法建立等维新息动态预测预报模型 ,并随着新数据的加入适时修改模型参数。该模型不要求考虑复杂的变形影响因素。工程实例研究表明 :用组合模型预测变形值 ,其误差大多数情况下小于 5 % ;在变形数据变化较大时 ,组合模型预测值明显优于单一模型预测值。在变形变化平稳时 ,用单一的灰色模型或灰色时间序列组合模型预测误差相差不大。预测步数越多 ,则预测精度越低。

A GREY TIME-SEQUENTIAL COMBINED MODEL FOR DYNAMIC PREDICTION OF HORIZONTAL DISPLACEMENT ON THE DEEP EXCAVATION WALL TOP

Horizontal displacement of the wall top of a deep excavation is a dynamic dependent process.During its excavation and construction,a equal intervals dynamic combined prediction model of recent information,in which grey system theory and time series analysis method is adopted,is established on the basis of measured data.With the addition of new deformation datum,the model parameters are continuously modified.The complicated factors influencing the displacement in the model are neglected.The practical displacement prediction of the pit has showed that the error between measure and prediction value is mostly below 5 percent.Under the condition of unstable displacement data,the combined prediction value is superior to that of the single grey model.But with the stable data,the prediction displacement value difference by combined or single model is little.The more prediction step,the more error.