Application of Discrete Grey Model in Settlement Prediction of High-speed Railway

The GM (1,1) model uses a discrete form equation to estimate the parameters and employ a continuous form equation to fit the model and predict the data sequence. The jump between the two form of equation is the fundamental reason to causing the error of GM (1,1) model. This paper first introduces the theory of the Discrete Grey Model (DGM (1,1) model), the solving method of model parameter and the solving algorithm of simulation value and the predicted value. Then, a modified DGM (1,1) model is proposed after analyzing the problems of Discrete Grey Model exited in the practical application. Finally, some contrast experiments for high speed railway subgrade settlement prediction are carried on by applying the improved DGM (1,1) model, the GM(1,1) model and the DGM(1,1) model respectively. The experimental results show that the improved DGM (1,1) model could acquire better model accuracy and forecasting result in engineering application.