基于非等时距GM(1,1)模型的公路路基沉降预测

Settlement Prediction of Highway Subgrade Based on Unequal Time-interval GM(1,1) Grey Model

基于灰色系统理论的灰色模型广泛应用于公路路基沉降预测。针对灰色GM(1,1)模型要求原始实测数据是等时距的特点,采用分段线性插值法将实测数据转化为等时距数据,建立路基沉降的非等时距GM(1,1)预测模型,并采用后验差法进行精度检验。以S353省道扬州西段软土和高填方断面实测沉降数据为基础,对模型预测结果进行分析。结果表明,该方法所得预测值与实测值比较接近,相对误差较小,模型精度等级为一级,证明非等时距灰色模型的可行性和有效性。

The grey model based on the grey theory is widely used in highway subgrade settlement prediction. According to the characteristics which the grey GM（ 1,1） model requires the measured data to be an equal time interval data sequence,the straight line interpolation is adopted to change the unequal time interval data sequence into an equal time interval sequence,an unequal time interval forecasting model of GM（ 1,1） is established and the precision of the model is verified by the posterior variance examination. The forecasting result is analyzed by using factual data of S353 highway Yangzhou westmiddle section soft soil and high fill subgrade. The results show that the predicted value are coincided with the observed value,the error is small between them,and Precision of model is first class,thus confirming the feasibility and availability of unequal time interval GM（ 1,1） grey model.