A parametric study was carried out to study the behavior of offshore anchor piles under mooring forces in dense sand using a three dimensional (3-D) finite element model (FEM). The Mohr–Coulomb plastic model has been used to model the soil, and has been calibrated based on the centrifuge tests discussed in a Ph.D. thesis (published by Ramadan in 2011). The selection of model parameters and comp...

C. G. Johnson, J. M. N. T. Gray (2010), J. Fluid Mech., (Submitted) • “Weak, strong and detached oblique shocks in gravity driven granular free-surface žows”, J. M. N. T. Gray, X. Cui (2007), J. Fluid Mech., 579, 113–136 • “Dežecting dams and the formation of oblique shocks in snow avalanches at Flateyri, Iceland”, X. Cui, J. M. N. T. Gray, T. Johannesson (2007), J. Geophys. Res., 112, F04012 •...

We numerically study the piles generated by continuously dropping a particle on the top of a stable pile in (I + I) dimension. We use a code which has an implementation of static friction in the Molecular Dynamics (MD) simulations of granular material. We study several properties of the pile-the time evolution of mass and slope, and the avalanche size (and duration) distribution. We also study ...

Offshore anchor piles are seafloor moorings that keep the position of floating structures during a harsh environment. These piles are usually subjected to a wide range of monotonic and cyclic lateral-to-oblique pullout forces. Centrifuge tests were carried out to study the behavior of offshore anchor piles under mooring forces in saturated dense sand. The tests were carried out at different loa...

We report experiments on piles of cohesionless granular materials showing the effect of construction history on static stress distributions. Stresses under piles are monitored by sensitive capacitive techniques. The piles are formed either by pouring granular material from a funnel with a small outlet (localized source), or from a large sieve (homogeneous rain). Localized sources yield stress p...

We relate the pressure "dip" observed at the bottom of a sand pile prepared by successive avalanches to the stress profile obtained on sheared granular layers in response to a localized vertical overload. We show that, within a simple anisotropic elastic analysis, the skewness and the tilt of the response profile caused by shearing provide a qualitative agreement with the sand pile dip effect. ...

We have investigated experimentally the influence of a magnetic interaction between the grains on the compaction dynamics of a granular pile submitted to a series of taps. The granular material used to perform this study is a mixture of metallic and glass grains. The packing is immersed in homogeneous external magnetic field. The magnetic field induces an interaction between the metallic grains...

Discrete numerical simulations are performed to study the evolution of the microstructure and the response of a granular packing during successive loading-unloading cycles, consisting of quasistatic rotations in the gravity field between opposite inclination angles. We show that internal variables--e.g., stress and fabric of the pile--exhibit hysteresis during these cycles due to the exploratio...

In this paper we study the steady uniform flows that develop when granular material is released from a hopper on top of a static pile in a channel. We more specifically focus on the role of side walls by carrying out experiments in setup of different widths, from narrow channels 20 particle diameters wide to channels 600 particle diameters wide. Results show that steady flows on pile are entire...

We have performed a systematic, large-scale simulation study of granular media in two and three dimensions, investigating the rheology of cohesionless granular particles in inclined plane geometries, i.e., chute flows. We find that over a wide range of parameter space of interaction coefficients and inclination angles, a steady-state flow regime exists in which the energy input from gravity bal...