关键词: 沉降变形; 变形预测; GM(1,1)模型; 坐标变换;

Abstract: The traditional GM(1,1)model uses exponential function for prediction, and the fitting function curve of the first accumulation data does not coincide with the first accumulation curve of the measured data, having a trend of closeness, intersection or separation between them, and it will lead to the error of first accumulated value of later prediction.Therefore, it was proposed to set up a plane coordinate system with sequence index(time)as the horizontal axis and sequence value as the vertical axis.In this coordinate system, the coordinate transformation of first translation and then rotation was carried out for the fitting prediction value of a cumulative sequence.After the transformation, the transformed points formed a new broken line, and then the ordinate value corresponding to the original abscissa on the new broken line or the broken line extension line was used as a cumulative final prediction value.After cumulative reduction, the late prediction value of the modeling sequence was obtained.The measured deformation data of two cases were used to verify this method, which was proved that it can effectively improve the prediction accuracy, has much reference value for practical engineering.

Key words: settlement deformation; deformation prediction; GM(1,1)model; coordinate transformation;