Research Of Laboratory Tests And PFC～(3D) Numerical Simulation For The Steady State Of Sand

The steady state of deformation for any mass of particles is that state in which the mass is continuously deforming at constant volume, constant normal effective stress, constant shear stress, and constant velocity. The steady state of deformation is achieved only after all particle orientation has reached a statistically steady-state condition and after all particle breakage. The steady state strength and the steady state line which are obtained by steady state deformation are the important parameters for estimating the stability of saturated cohesiveless soils. Now the behavior of steady state deformation for saturated cohesiveless soils is not well known to us yet. Many questions have no conclusion.Steady state strength is an important parameter in evaluating the stability of sand deposits against flow liquefaction. Formerly, the research of steady state strength of sand is mostly based on laboratory tests such as triaxial compression tests. But there is much limitation in laboratory tests. The structure of traixial tests apparatus and methods used for sample reconstitution both will greatly affect the results of tests.Compared with methods of laboratory tests, methods of numerical simulation are much more convenient, and that, methods of numerical simulation can ensure the identity of initial sample of sand. The particle flow code (PFC) theory is introduced and the particle flow numerical simulating method is developed in the paper. PFC is not restricted by the macrocosmic continuity hypothesis that used in other continuum simulating methods. Series of triaxial tests of sand are simulated for the further research of steady state of sand.A series of drained triaxial compression tests were performed to investigate the deformation characteristics and steady state of sand. The test results show that the steady state strength of sand doesn抰depend on the initial density of sand and the effective mean normal stress. The results also indicate that the steady state of sand is the essence of sand. The unique friction angle of sand were testified .In this paper, numerical simulation(through PFC^3D) results of deformation...