Unified strength criterion for soils, gravels, rocks, and concretes

There are both diversity and unity in the strength characteristics of different geomaterials and concretes. Based on the generalized nonlinear strength theory, a simple but unified strength criterion (USC) is proposed for various materials, such as soils, gravels, rocks, and concretes. Power function is used as the failure curve of the USC in meridian plane, while the shape of failure curve in pi-plane is curved triangle, which is between the SMP and Mises criterion. With only four independent parameters, which are convenient to be determined, the proposed criterion is able to take the effects of friction, cohesion, hydrostatic pressure, and intermediate principal stress into consideration. The proposed criterion is compared with some widely used unified strength criteria, such as the Zienkiewicz-Pande criterion and the Lade criterion, against the experimental results for various soils, gravels, rocks, and concretes. The comparison between the predicted and observed results confirmed the validity of the proposed criterion used as a USC for geomaterials and concretes.