Several basic problems in plastic theory of geomaterials

摘要

Based on the basic mechanical properties of geomaterials,it was proven that the Drucker Postulate and the classical theory of plasticity can not be applied to geomaterials.Moreover,several basic problems of plastic theory of geomaterials were discussed.Based on the strict theoretical analysis,the following have been proven:the single yield surface model based on the classical theory of plasticity is unsuitable for geomaterials whether the rule of associated flow is applied or not;the yield surface of geomaterials is not unique,and its number is the same as the freedoms of plastic strain increment;the yield surface is not convex;and the rule of associated flow is unsuitable for geomaterials.