Isfahan University of Technology Journal of Computational Methods in Engineering 2228-7698 36 2 2022 12 31 An Improvement of Vermeer-de Borst Constitutive Model for Numerical Simulation of the Shear Behavior of Rockfills An Improvement of Vermeer-de Borst Constitutive Model for Numerical Simulation of the Shear Behavior of Rockfills 49 62 3166 10.29252/jcme.36.2.49 FA M. Salari Journal Article 2022 12 31 The most important features and phenomena of the deformation behavior of rockfills are stress-dependent stiffness, hardening and dilative (or contractive) behaviors, as well as breakage, rotation and redistribution of particle size. An elasto-plastic constitutive model has been suggested by Vermeer and de Borst to simulate the shear behavior of soils, concretes and rocks. This research has tried to improve this model for numerical simulation of the shear behavior of rock fills. The improvement of the model has been performed through proposing new mobilized dilation and friction angles functions and new relationships for some parameters. For validation, a series of large-scale triaxial tests performed on the rockfill shell of Masjed-e-Soleyman dam have been simulated with the improved model. The results show that the improved Vermeer-De Borst model has a good accuracy to simulate the shear behavior of rockfills numerically. The most important features and phenomena of the deformation behavior of rockfills are stress-dependent stiffness, hardening and dilative (or contractive) behaviors, as well as breakage, rotation and redistribution of particle size. An elasto-plastic constitutive model has been suggested by Vermeer and de Borst to simulate the shear behavior of soils, concretes and rocks. This research has tried to improve this model for numerical simulation of the shear behavior of rock fills. The improvement of the model has been performed through proposing new mobilized dilation and friction angles functions and new relationships for some parameters. For validation, a series of large-scale triaxial tests performed on the rockfill shell of Masjed-e-Soleyman dam have been simulated with the improved model. The results show that the improved Vermeer-De Borst model has a good accuracy to simulate the shear behavior of rockfills numerically. https://jcme.iut.ac.ir/article_3166_5e6d27a7a8a8330df4b53240737ccc85.pdf