In order to determine nonlinear constitutive model parameters of rockfill materials

the inversion procedure based on response surface method is proposed. The sequential impoundment processes of concrete-faced rockfill dam are simulated by using nonlinear finite element method. The response surface functions of forecasting dam settlement for every observing point are presented. The coefficients of response surface function are calculated. Model parameters of nonlinear constitutive relationship of rockfill materials are determined using observed deformations after dam construction and response surface functions of forecasting dam settlement. The practical applications show that the proposed inversion procedure is of higher computing efficiency; and the forecasted dam settlements agree well with observed values.