Permafrost subgrade deformation forecast based on phase space reconstruction and partial least squares regression

In order to accurately forecast permafrost subgrade deformation, a single variable chaos time series of permafrost subgrade deformation was constructed in multidimensional phase space, some independent variables, function and sample numbers were defined according to embeded 38 dimensions of the space, the main components of independent variables were picked by using partial least squares regression method, a deformation forecast model was constructed, the precision of the model was analyzed by recurring multiplicate evaluation indices, and the comparative figure between forecast values and measure values was plotted.Analysis result shows that all sample points concentrate near the diagonal line of the figure, their correlation index is 0.889 4, their maximum relative error is 9.75%, which indicates that the model is reasonable and credible, can forecast subgrade deformation in permafrost regions.