Hypoplastic Model with Intergranular Strain: Dependence on Grain Properties and Initial State

Abstract

The Hypoplastic model is introduced and the procedure to determine the model parameters along with intergranular strain parameters is discussed in detail. Static trial tests and load/displacement controlled oedometer tests are performed to determine the hypoplastic model parameters. The dependence of the hypoplastic model parameters on initial density of granular materials is studied. Intergranular strain parameters are conventionally determined by resonant column tests. An innovative method based on static triaxial setup coupled with stress path test method is employed to determine the intergranular strain parameters. Parameters are determined for 5 different naturally existing sands. The dependence of the model parameters, on density, stress state and grain assembly properties of the sand is studied. The elastic strain range within which the incremental stiffness remains constant after strain reversal is studied in conjunction with the grain properties and the validity of the assumption that the governing parameter is a material independent constant is commented upon. The model parameters are verified against results of standard element tests.