Winlong,

We have analyzed stockpile forces and its surrounding soil with its pressure gradients including embedded tunnel/bunker designs using two methods:

1. Finite Element Method (FEM)

2. Discrete Element Method (DEM)

DEM seems to give a better picture. This field is relatively unexplored based on our literature search. To my knowledge, there have been few scientific investigations on the true nature of changing soil pressures within the stockpile and surrounding elastic-plastic foundation structures, differing stockpile configurations, and non-homogeneous soil rheology and responses.

The more difficult properties to obtain are the soil orthotropic properties such as elastic and shear moduli in three planes that change with pressure, material properties, structural shape, and stockpile physics.

We did make an attempt at it.

The changes in the elastic foundation response can have some interesting conditions. We noticed there is more than one mode peak depending on the shape of the pile and its withdrawl configurations. Is this true?

I will watch the responses and anticipate enlightenment, sharing your hope of a better more informed answer.

Thanks for the Question.

Lawrence Nordell

President

Conveyor Dynamics, Inc.

email: nordell@conveyor-dynamics.com

website: www.conveyor-dynamics.com ■