摘要
RSA(rock and soil associate) is inhomogeneous and discontinuous,and the stress distribution inside the materials is uneven while external forces are applied on them.For these materials,the real boundary condition is the equal stress boundary condition.The existing soil mechanics testing machines are loaded by rigid boundaries,i.e.,the equal displacement boundary loading.This testing machine is not suitable for inhomogeneous material.In order to eaxime the mechanical behavior of RSA or fractured rock,a new type of triaxial compressive test machine with equal stress boundary loading is developed,using flexible head and base,imposing the equal stress boundary conditions.Difference in shear strength parameters of RSA under two boundary conditions are studied.And,we carried out numerical calculation with the software CDEM.The results show that the parameters obtained from the equal displacement boundary loading is 20% greater than the parameters obtained from the equal stress boundary condition and they tend to be unsafe.