ANALYSIS OF VERTICAL STEEL SILOS

Abstract

Silos are being used in a wide variety of industries. It has applications in the mining, power generation, steel making, quarrying, plastics, chemical processing, food processing, whisky production, farming and agricultural industries, where materials have been stored ranging from agricultural grains and their flours, many coals, crushed rocks and mineral ores, plastic and polyethylene pellets and powders, and chemical process powders. Steel silos are much lighter structures and place smaller loads on their foundations. Thus, steel silos are widely used now a day for storage of materials. The analysis of these require profound knowledge of plates and shell structures. In the present study two different theories regarding the analysis of Silos have been discussed with importance to Janssens theory, which is used in the Indian code. Different variables affecting the behavior of the silo like horizontal and vertical pressure variation along the depth of a silo, pressure ratio and coefficient of wall friction have been studied. There are many pitfalls, many strange paradoxes and a number of phenomena, which are counter-intuitive in silos and they have been tried to be mentioned in this thesis. This thesis is intended to provide useful information and guidance, together with methods of assessing bins for features previously standardized, and explanations that assist with the use of the IS : 9178 (Part I) and IS : 9178 (Part II) standards. Excel sheets have been developed for the analysis of Silos and Bunkers. These can be used for a variety of materials with different properties that are intended to be stored.