Study on Displacement Prediction of Completely Weathered Slope Based on Set Pair Analysis and Combination Theory

The displacement of weathered granite slope is affected by many uncertain factors, resulting in complicated uncertain problem for its prediction. A weathered granite slope in Ping-Yi Expressway was taken as the study object. Based on a small number of monitoring data, five single prediction models were established. Then, the set pair relationship between each single model predicted value and the measured value was quantitatively analyzed based on the set pair relation criterion, and the combination weight coefficient was determined by the relation number.Finally,the combined prediction model of slope displacement was established, and the predicted value was compared with the measured value. The study shows that the optimal combination of prediction information is realized by using the set pair analysis and combination theory. Compared with the single model, the maximum relative error of the combined model is less than 20%, and the absolute error square SSE, standard error SSE as well as other indicators are small, which can provide a more reliable basis for dynamic slope construction management. The application scope of the set pair analysis and combination theory is expanded, and ideas for solving displacement prediction problems of other similar projects are provided.