Anisotropic stiffness and strength of concrete rock mass equivalent with sets of persistent joints

• Published in: Computers and geotechnics Vol. 169; p. 106193
• Main Authors: Hua, Dongjie, Zhang, Guohua, Xiong, Feng, Tang, Zhicheng, Jiang, Qinghui
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.05.2024
• Subjects: Concrete specimen; Equivalent continuum model; Rock mass; Strength; Equivalent continuum model; Concrete specimen; Rock mass; Strength
• ISSN: 0266-352X; 1873-7633
• DOI: 10.1016/j.compgeo.2024.106193

The joint network significantly influences the mechanical behavior of rock masses. The anisotropic stiffness and strength of the rock mass are analyzed in this study by means of laboratory tests, theoretical derivations and numerical simulations. Firstly, biaxial compression tests are performed on cubic specimens with a side length of 300 mm under lateral stresses of 0 MPa, 1 MPa, 2 MPa, 4 MPa and 6 MPa. The failure modes of concrete rock mass equivalents are influenced by the joint geometric configuration and stress state. Secondly, a constitutive model to describe the anisotropic stiffness and strength of jointed rock masses with sets of persistent joints is proposed by an equivalent continuum approach. The limitations of the present equivalent approaches are discussed. The proposed model is subsequently implemented in FLAC 3D based on the user defined model (UDM), of which the simulated results are compared with those of the distinct element method code UDEC. The good agreement between the two approaches verified the effectiveness of the proposed model. Finally, the predicted stiffness and strength of the concrete rock mass equivalents are compared with the measured results of laboratory tests based on a parameter calibration procedure, where good agreement can also be found.