Application of Grey Verhulst Model in Settlement Prediction of Soft-Soil Subgrade

摘要

The settlement calculation of soft-soil subgrade is one of the most important problems in the filed of Geotechnical Engineering. Because of the uncertain factors about preferences and outside conditions in settlement calculation, especially, in settlement analysis for the over deep silt ground, if we adopt traditional calculation method, the precision of results will be not high. The precision of the prediction method based on the observed settlement data will be higher. Nevertheless, different methods in this class have different advantages and applicability. So, proper settlement prediction method should be chosen for each case according to the actual conditions. The grey system theory could be used to deal with the problems of the systems with incomplete information, and there are not any special requirements for the data. According to the grey system theory, grey Verhulst prediction model is established based on the settlement observation data of Lingni Seawall in Wenzhou city. At the same time, one corresponding computer procedure is compiled by MATLAB language to predict the settlement of the seawall. Compared the predictive results by grey Verhulst model with the results by hyperbola method, the analysis shows that, the precision of grey Verhulst model is higher, the relative error is smaller than hyperbola method's. Grey Verhulst prediction is one of the effective and feasible methods in settlement forecasting of soft-soil subgrade.