A new yield and failure criterion for geomaterials

This paper proposes a new isotropic yield and failurecriterion for geomaterials under general stress conditions.The new criterion is a function of the three stressinvariants and the paper shows the well known criteriaby Matsuoka & Nakai (1974) and Lade & Duncan (1975)are included in the new formulation. In order to includedifferent features characterising soil and rock behaviour,the obtained function is successively modified to accountfor tensile strength and curvature in meridian planes.The influence of each parameter is discussed and finallythe comparison between the new criterion and someexperimental data on soils and rocks is shown. Finally,the domain of the new criterion is analysed in order toshow if the yield function takes negative values alsooutside the shown elastic domain.