Abstract: Through a thorough study on the settlement development regularity of soft clay embankment and its settlement curve characteristics, based on every single S-type forecasting model and 5 types of S-type curves, and with the idea of combination prediction, a forecasting method and theory for settlement development of soft clay embankments are discussed emphatically; and a variable-weight combination of S-type curves is put forward for forecasting soft clay embankment settlement. Applying the mathematical programming method, the settlement development course of soft clay embankment can be forecasted by limited observed settlement data. The analytical result of engineering practice indicates that the forecasting curve obtained by this model and method can fit well the measured curve, which can meet engineering demand; what’s more, the variable-weight combination forecasting model is obviously superior to other single model so as to provide an effective and practical method for forecasting settlement development of soft clay embankments.

Key words: highway engineering, soft clay embankment, settlement, variable-weight combination forecasting model, S-type curve