Abstract: Three-dimensional bounding surface constitutive model for rockfill materials incorporating the general nonlinear strength criterion can well capture such behaviors of rockfill materials as the strain hardening, the post-peak strain softening, and the volumetric strain contraction and expansion in the three-dimensional stress space, which cannot be predicted by the traditional constitutive model proposed before. Based on the theory of 3D bounding surface constitutive model and according to the further developing platform provided by FLAC3D, the 3D bounding surface model is successfully developed in FLAC3D with VC++ environment; and then key steps, programming essentials and methods of constitutive model’s secondary development are given based on FLAC3D code. The calculative results of 3D bounding surface model using FLAC3D under general triaxial compression tests are compared with the theoretical values. The results are turned out that the calculative results can aptly fit the theoretical values and predict the behaviors of rockfill materials. In particular, model parameters of bounding surface model are simple and can be determined by general triaxial tests. Therefore, we can see that it shows the superiority and reasonableness of 3D bounding surface model’s procedure.

Key words: rockfill materials, 3D bounding surface constitutive model, FLAD3D, further development, verification