Prediction model for settlement of high-speed railway embankment in unsaturated areas

The precise prediction of post-construction settlement for high-speed railways is one of the key techniques in successful construction of high-speed railways. The in-situ observation data show that the shapes of settlement vary greatly under different unsaturated conditions. Limitations and risks are observed to predict unsaturated settlement using the traditional predication methods based on the saturated theory. A new prediction method for post-construction settlement of unsaturated high-speed railway embankment is proposed. The characteristics of the proposed model are analyzed, and the solving algorithm for the model is developed. Based on the observed settlement data in LXS-15 of Lanzhou-Xinjiang Double-Line Railway, predictions are carried out respectively using the proposed model and other three methods. By defining the correlation coefficient, deviation degree and stability property as the evaluation indices and using 2 years' continuous in-situ observation data, the prediction precision is investigated and compared. The applications in three sections with different saturations show that the proposed settlement prediction model is feasible and scientific for unsaturated embankment of high-speed railways, and it may provide a method for prediction of post-construction settlement of high-speed railways in unsaturated areas.