3-Dimensional Modelling for Direct Shear Test of Structure Plane in Rock Mass

Direct shear test is an important test in geotechnical engineering to obtain the basic parameters of the rock mass. In order to study the three dimensional characteristic of structure plane during the direct shear test, the numerical simulation software FLAC3D is used to build the calculation model for the structure plane under the compound stress of normal direction and shear direction. The deformation and mechanical response of the structure plane are analyzed, which show that, (1) Relationship between shear strength and normal stress meets in the Mohr-Coulomb linear way, which is the same as the laboratory test and theoretical analysis; (2) the distribution of stress on the structure plane increases from the side of loading to the other side; and with the increase of normal stress, while the distribution of maximum shear stress does not vary greatly. The analysis results can give some guidance for the real practice; (3) the result from the numerical modeling method is close to that from the laboratory test, which confirms the validity of the numerical method.