Edge effect of the tank wall-bottom joint on service reliability of vertical steel tank

Abstract

The paper presents the analysis of the edge effect in the wall bending of a vertical steel tank RVS-20000 using a comparison between the results obtained by using the bending theory and membrane theory. It is shown that the condition of the wall-bottom joint strength is satisfied in both cases.The stresses obtained according to the bending theory with regard to multiplying safety factor, exceed the maximum stresses by 11.1 % obtained by using the membrane theory with account for the edge effect. This makes it possible to use the membrane theory equations in calculating the wall thickness, which excludes complex calculations of the bending theory. Unlike the membrane theory, the membrane theory provides the stress and strain calculation of the T-junction. The results obtained indicate that the service reliability of the wall-bottom joint is primarily determined by the preparation quality of the tank base, welding quality of the T-junction (including negative temperatures) and the methods of their flaw detection on the construction site.