Extended twin shear strength

Lade-Duncan and Matsuoka-Nakai failure criteria

could capture some important strength failure characteristics such as tensile stress

friction

and curved meridian et al.of geo-material with good accuracy.Based on true triaxial test data of red sandstone and target error function established between testing values and predicting values

corresponding parameters of the three failure criteria are identified through searching minimum values of the target error function.Bas...