Vertical Stress Isobars for Silos and Square Backfilled Mine Stopes

Abstract

Often granular materials are stored in vertical containers with circular or square cross sections. The storage material can be food grains, pharmaceutical powders, chemical pellets, or geomaterials such as mine fills. The design and analysis of these containers require adequate knowledge of the stresses developed within the filled material. The stress isobars developed herein enable the designers to estimate the vertical stress at any point within the fill contained in a silo. The same isobars can also be used for square cross sections, as in the case of backfilled underground mine stopes, without sacrificing the accuracy much. The same method was previously followed by the authors in developing isobars for plane-strain situations. On the basis of the two sets of isobars for trenches and square stopes, it is possible to interpolate the stresses for other rectangular mine stopes, which can serve as good first estimates in the designs.