Abstract：Slope stability analysis was carried out using strength reduction finite element method(FEM) based on the Drucker-Prager criterion. The definition of slope stability safety factor based on the Drucker-Prager criterion was proposed，and the safety factor conversion formula with different Drucker-Prager yield criteria was deduced. The substitutive relationship of safety factor based on the Drucker-Prager yield criterion and Mohr-Coulomb yield criterion was set up. Currently，the Mohr-Coulomb hexagon circumcircle Drucker-Prager criterion was adopted in the ANSYS programme. So，the safety factor using ANSYS with the Mohr-Coulomb hexagon circumcircle Drucker-Prager criterion is calculated，thus the safety factor based on the Drucker-Prager yield criterion(such as the Mohr-Coulomb matching Drucker-Prager yield criterion under the plane strain condition) can be obtained using the deduced conversion formulae. Under the plane strain condition，the Mohr-Coulomb yield criterion in the ANSYS programme without secondary programming development through equivalent substitution is adopted. A series of case studies indicate that the average error of safety factors between those obtained by strength reduction FEM based on plane strain Mohr-Coulomb matching D-P yield criterion and those by Spencer method is 1%–2%. The applicability of the proposed method was clearly exhibited.
