A study of the energy yield criterion of geomaterials

作     者：Gao Hong Zheng Yingren Feng Xiating Zeng Jing 

作者机构：State Key Laboratory of Geomechanies and C.eoteehnieal Engineering Institute of Rock and Soil Mechanics Chinese Academy of Sciences Wuhan 430071 China Department of Civil Engineering Logistical Engineering University of PLA Chongqing 400041 China 

出 版 物：《Engineering Sciences》 (中国工程科学（英文版）)

年 卷 期：2010年第8卷第3期

页      面：12-20,40页

学科分类：08[工学] 080104[工学-工程力学] 0815[工学-水利工程] 0801[工学-力学（可授工学、理学学位）] 080102[工学-固体力学] 

基　　金：National Natural Science Foundation of China (No.50609027) 

主　　题：岩土材料 屈服准则 能量准则 中间主应力效应 作者 能源系统 统一标准 摩擦特性 

摘      要：The study results of the internal friction character of geomaterials conclude that the internal friction exists in mechanical elements all the time having a direction opposite to the shear stress,and the deformation failure mechanism of geomaterials greatly differs from that of metals. For metals,the failure results from shear stresses make the crystal structure slip; whereas for geomaterials,owing to its attribute of granular structures,their deformation follows the friction law,it is the co-action of shear stresses and perpendicular stresses that makes grains overcome the frictions between them,thus leading to the final failure of relative ***,on the basis of the cognition above,a triple shear energy criterion is proposed. Its corresponding Drucker-Prager criterion for geomaterials is also given. The new criterion can be rewritten to the Mohr-Coulomb criterion by neglecting the effect of the intermediate principal stress,and to the Mises criterion by not taking the internal friction angle into consideration. Then the studies of yield criteria commonly used are conducted systematically from the points of stress,strain and energy of geomaterials. The results show that no matter which expression form of stress,strain or energy is used for the yield criterion,the essence is the same and the triple shear energy yield criterion is the unified criterion of materials. Finally,the experimental verification is conducted in connection with the practical application of the triple shear energy yield criterion in an engineering project,and the calculation result shows that the Mohr-Coulomb criterion which only takes the single shear surface into account is more conservative than the energy criterion that does consider the effect of triple shear surfaces.