Abstract:After comparing the difference of materials properties and the induced difference of mechanical characteristics between metals and geomaterials,it is concluded that geomaterials are frictional materials with multiphase and have frictional characteristics. By analyzing the mechanical elements of two kinds of materials,it is considered that there are frictional stresses in the mechanical elements of frictional materials. By generalizing the Tresca yield criterion and the Mohr-Coulomb yield criterion,the energy yield criterion considering only simple shear surface is deduced,which proves that the Tresca yield criterion and the Mohr-Coulomb yield criterion are the simple shear energy yield criteria of metals and geomaterials,respectively. The energy yield criterion about three shear surfaces is discussed;then the triple shear energy yield criterion and corresponding Drucker-Prager yield criterion of geomaterials are established. The Mohr-Coulomb yield criterion and the triple shear energy yield criterion are used to validate the true triaxial test data. The errors show that the results of the triple shear energy yield criterion are more close to the test data than those of the Mohr-Coulomb yield criterion,which proves that the energy yield criterion is correct. At last,a simple slope is computed using the Mohr-Coulomb yield criterion and the triple shear energy yield criterion respectively;and the results indicate that the Mohr-Coulomb yield criterion is more conservative than the triple shear energy yield criterion.