sand mortar models are conducted. Though analysis and fitting of the results obtained from model experiments
an initiatory increment constitutive model of unloading jointed rock masses is proposed. Aiming at deficiency of the constitutive relationship
new model through amendment based on parameter choosing and physical meaning is obtained. Then the constitutive relationship is incorporated into ADINA
the analysis for the high slope model of Geheyan Hydropower Station is performed; and the calculation results are compared with those by loading method. The rationality of the constitutive relationship is verified finally.