3D computer simulations and experiments are employed to study random packings of compressible spherical grains under external confining stress. In the rigid ball limit, we find a continuous transition in which the stress vanishes as (straight phi-straight phi(c))(beta), where straight phi is the (solid phase) volume density. The value of straight phi(c) depends on whether the grains interact vi...

The rockfill is modeled as nonlinear elastic material, whose stress-dependent tangent modulus is related to the confining pressure. The parameters of constitutive relationship of stress and strain are determined by tri-dimensional compression test in laboratory. The model applied in this study adopts the technique of element birth and death to simulate the sequential impoundment process of conc...

In order to study the damage evolution law of coal under seepage-stress coupling, this paper adopted rock servo triaxial test system conduct permeability for full stress-strain process on 10 sets specimens using steady-state method different confining pressure and osmotic pressure. The results show that has a small fluctuation before stress peak, increases substantially after peak. relationship...

Random packings of granular chains are presented as a model system to investigate the contribution of entanglements to strain stiffening. The chain packings are sheared in uniaxial compression experiments. For short chain lengths, these packings yield when the shear stress exceeds the scale of the confining pressure, similar to granular packings of unconnected particles. In contrast, packings o...

The behavior of sand crushing will appear when the confining pressure is up to a certain value, which results in disappearing of the positive dilatancy of sand. Adopting a new hardening parameter with the crushing stress, an elastoplastic constitutive model considering sand crushing is proposed. Comparing the conventional triaxial compression test results with the model prediction, it shows tha...