Determination of spatial earth pressure on circular shaft constructions

Abstract

Based on the Distinct Element Method, three dimensional calculations were carried out to determine the spatial earth pressure of sand on circular shaft constructions with respect to their deformation. For this purpose the commercial program PFC^3D has been applied using a linear sliding contact model. The program confines itself to homogenous rigid balls. To define the required parameters (normal stiffness k _n, shear stiffness k _s and contact friction μ), the well known plane earth pressure according to Coulomb is calculated as calibration. Due to the rotational symmetry, the spatial earth pressure calculation is limited to only one sector. Simultaneous model tests were executed to check the results. Although a simple DEM with only a few parameters is applied, the calculation results fit very well to those of the tests and classic theories.